A guide that introduces you to the basics of the Noisy Tenant universe with the aim of helping you understand how things work. Below is a list of things in alphabetic order you will hear about frequently with their explanations. It is recommended to first start off with zones for ease of understanding. If you have confusions or suggestions for things to add, feel free to say in the comments.
Absurdity
Yeah, it happens a lot. Some events in the series are absurd and make no sense. But that's because of our lack of understanding or because of the alien ways things work in some worlds.
Anatomy
Characters have a very different anatomy than ours. I mean, how would you expect a living organ to function? Some entities see us as multiple organs that weirdly enough don't work on their own. There are also non-matter organs that even we have, but don't perceive them. More info on the subject here.
Art shift
Tied with perception and how our feelings and mind affect it. In the series we encounter characters, objects and places that have a different art style than the rest. From doodles, cartoony, realistic, photographic, photoshoped, pixelated, 3D and other styles, it's something about how we can perceive it.
Awakened and Unawakened
The term awakened may refer to those that became aware about the zones and such. Most non-human characters are like this while most humans are unawakened.
Bioform
Simply refers to what type of lifeform a creature is. It isn't limited to just what be call organic, bioforms can be animate objects and anything else that doesn't have organic matter.
Bleed or Leak (Zonal)
A zonal leak is when some element or concept from a zone gets in an another zone. Leaks can create connections between zones, like when Burgrr bleed into The Hospital. Another example is the concept of The Hospital leaking into the grey zone creating pseudohospitals (the real world hospitals).
Blogs and Journals
Some characters have personal blogs and journals. The way they write them is totally alien to us, as they can update even when they shouldn't be able to, no matter in what situation they are. You can see the link to a character's blog on its wiki page.
Branches and Branchination
While zones have an infinite number of layers, which are similar to alternate timelines, entities have a finite number of branches. Branches are like those timelines where you exist, and some of them end with your death. Humans normally have a single branch, meaning that their death is permanent. Other entities can generate (or germinate) new branches, a process called branchination. It is essential to prevent permanent death.
Broken Language
Written words are often misspelled. Some entities also speak with broken grammar and gibberish. That's because their language is imperfectly translated for us.
Cones
Are mentioned often and have quite the meaning. Cones can be similar to body parts and on some occasions are referred to as an entity. "The cone was lied before, and it could lie again."
Concept
Everything exists out of concept. The first step for something to exist is to be conceptualized. Then, from the concept, it can manifest a concrete form. Entities and zones alike are born from concepts. Only from conceptualizing a thing you already make it happen somewhere.
Consciousness
In the most general sense, consciousness is an ability of some living object to perceive and recognize the surrounding reality. Some objects can look inanimate to us but can also be perceiving from their own point of view. Even more abstract things such as sounds can be living beings in some perceptions or others.
Core
The center of every being and the primary concept of its own existence. Cores connect to concepts with their branches, and one core can lead to multiple beings, also called perceptoids. Cores don't actually exist and are not real. Regular grey zoners only have one perceptoid and it carries their core within it. Without any perceptoid to maintain it, cores cease to exist, meaning that humans normally die for good. Most cores are capable of objectual-subjective adaptation, meaning they can generate multiple specialized perceptoids adapted to their appropriate manifestation zone. In other words, there are multiple versions of you in other zones that look different. For more information, read this book.
Cycle
One of other miscellaneous units of layers. It is a longer unit of what we may call "time", closely analogous to "years". There are more words used for subdivisions of layers such as spirals, quasispirals and others.
Death
For most non-human characters death isn't permanent and is just a minor nuisance at best. As long as you can branchinate and have multiple perceptoids you don't truly die. For achieving true permanent death you most destroy the core. Without any perceptoids, a core ceases to exist.
Exospine
An anatomical part that apparently everyone has. Even humans have it but don't have the necessary glands to perceive it. Exospines are essential in branchination and zonal travel. Unfortunately for grey zoners, their exospines are damaged by the Furlers that feed on them during infancy. This leaves them stunted and isolated to the rest of reality, being stuck in their matter zone.
Fourth Wall
Now why would we need one of those? In Awful Hospital, Dr Phage speaks directly to the readers at one point, in addition to the fact that Fern is controlled by them. Fern has also snapped at the commenters twice, once without actually knowing what they were and once snapping a suggestion box in half and yelling at them.
Furler
A Furler is an organelle of the Seething that is used for advanced gel swapping. More info in how to do this can be found in its Borfladge Dorcorm article or its wiki article. Furlers are known to feed on their favorite source of potassium, the exospines of infant grey zoners, leaving them stuck in their matter zone and unable to travel to other zones.
Gels
An unseen thing living beings have. Gels can be classified as exogels and endogels. Their role is left unexplained to the readers. There are multiples gel layers and gel types. Gel swapping can be done with a Furler, which takes what it need and replaces it. In Don't Get Spooked a Furler gives the player "life gel", which can be used to give life to inanimate objects.
Idea
Ideas may or may not be the same thing as concepts and are likely to be a stage before developing into full fledged concepts.
Inventory
Most non-human characters have a video game-like inventory mechanic with their own number of slots. At a glance, characters can look like they don't have any pockets or means of storing items but they are able to store them outside of conventional sight and space. Each inventory slot can hold only one concept at a time and also multiple instances of the same item, such as stackables. For example, someone with two inventory slots can't carry three different items but can carry three or more of the same item. Inventories can hold sometimes items that have a high weight or volume relative to the character, each slot having seemingly infinite space. Inventory slots are in some cases called inventory bladders. Those who lack a personal inventory system can use bags or other storing objects with such a system.
Language
Unlike humans, other characters speak on more than a vocal level. The intention they want to communicate is translated in an understandable form for the receiver. This is the reason why everybody seem to speak English to us. Even writing has this translation effect. However, translation isn't always perfect and we may end up with spoken or written broken language. If we don't have a word in our own language for something, we will get the closest approximation for it. That seems to be the case for things such as branchination, reverberators, exospine, among others. Some creatures can have such an alien language that we can't understand it. Their speech can be represented by photos, photoshopped images, emoticons and by other unconventional and abstract means. There are also languages that have harmful effects on certain bioforms. The most basic and simple form of communication uses images (emojis) instead of regular characters and that convey broad ideas. As a downside sending messages using this language can sometime be confusing, unpredictably misinterpreted or not understood at all by the receiver.
Layers
Possible conditions of a certain zone, which all beings inside constantly move through. For humans, this movement is straight and linear, forming experience called "time". For non-humans it can by quite different. Instantaneous jumping to distant layers is also possible - in this case new layer will look like a completely another "timeline". In webcomics it's common to refer to pages as layers.
Local Rules
Each zone was its own set of rules. One of the most well known ones are battle mechanics.
Perception
Perception is key in everyone's existence. Things that aren't perceived by other things can't exist. Even if we have moments when we think we are alone, there still are conscious things perceiving us but we may not see them as such. Your furniture can have a life of its own and sees everything from a different perspective. Everyone's perception is different and subjective, even people of the same species can see things slightly different than the other. What looks in a way to us can look totally different to others.
Perceptiograph
The equivalent of a photograph, but probably more complex. These are also subject to a translation effect in which the perceiver sees them as the closest thing they can comprehend and resembles the real thing.
Perceptoid
Just another word for someone's body and alternate selves. We all have a core that defines our very being and we can have multiple perceptoids/bodies in different layers and zones. Perceptoids in different zones may not look the same because they are adapted to their native zone. Death is actually the destruction of just a perceptoid, which are renewable by means of branchination. This is why apparent death isn't permanent and considered a minor nuisance. Only by eliminating all perceptoids the core is destroyed, and since grey zoners normally have only one perceptoid they permanently die. It is impossible and paradoxical for more than one of someone's perceptoids to be present in the same layer.
Purge
Unlike an ordinary kill, purging resets someone's history back to a specific point. They won't remember being purged and depending on the level of purging others can forget them (or never met). If a purge is strong enough, it can even permanently erase someone from existence. Purging is usually reserved for desperate situations where it would be a better alternative.
Respawning
Since almost every character branchinates, killing them only destroys a branch, leaving other branches to return. Death is just a minor setback and characters can respawn back to life. The Hospital is also known to rebuild other's vessels.
Reverberators
Parasitic things that are like cores and don't exist anywhere. Can't branchinate by themselves and need another core to manifest themselves into reality.
Schrode
A medical procedure where someone's core is put in a limbo state where it simultaneously exists and doesn't exist. From the outside they are not present anywhere and are not conscious perceivers. Opting for a schroding is the equivalent of suicide/euthanasia for beings that no longer wish to be a thing.
Sensory Mismatch
Zonal residents possess many unique types of sensations and have a number of senses are way more than humans are equipped. It's a wild variety of senses out there and for example some may lack the conventional ocular vision but make up in sensing vibrations or other outwardly things. There's also things like tasting colors, feeling angles, smelling thoughts, listening diagonally, seeing sounds and other weird things.
Shift
Generally a term used when someones goes from a zone to another.
Spirals and Spiralings
One of other miscellaneous units of layers. They are different units of what we may call "time". There are more words used for subdivisions of layers such as cycles, quasispirals and others.
Subjective Reality
Reality is subjective and everyone perceives things very differently. Therefore things don't have a single correct physical description as everyone's interpretation is equally true. Even beings from the same species can see things slightly different than the other.
Manifestation or Congealment
Refers to something coming into being. At first, things start from an idea or concept before taking a tangible form in our reality.
Matter
Not everything we see in this setting is made of matter or just matter alone. Our world, the grey zone, is classified as a matter zone. Some entities can also shift between a matter form and a non-matter form. There's even a thing called phantom organs that even humans possess.
Membranes
The term is often used for things that at least superficially function as membranes. We hear this word because it's the closest approximation in our language. One example where the word membrane is used are membrane layers.
Morality
Many character's morality is confusing or misleading for readers. We are often fooled to think some monsters have ill intentions but often that's not actually the case. There are some that would do harm but not out of malice, as death isn't permanent and just a nuisance for most. There's also the case where someone doesn't know that grey zoners don't usually branchinate and begin to wonder why they don't come back after being killed. Just because some characters are antagonists and act against us it doesn't mean they are evil, they may have good intentions that we fail to understand. That doesn't mean there aren't any true villains thou.
Nodes and Nodules
Especially mentioned in Borfladge Dorcorm articles, we can't understand what they are exactly but there're hints that they could be some anatomical parts of us. The words nodes and nodules are just the closest approximation for something we don't have words for in our language.
Non-Euclidean Geometry
We humans have a limited set of senses and move only in three dimensions (which is considered really low by other characters), so we aren't properly equipped to navigate most other zones. We have limited perception of such places and often we see doors that impossibly lead to rooms that are bigger than it would normally seem from the outside. Or two doors in a corner that would have rooms intersecting. Other mind boggling things are tote bags that have a number of infinitely sized compartments that occupy the same space or cupboards, closets and drawers that carry over their contents so you can access items you left in one and retrieve them from another one.
"Time"
A way of layer perception in humans. Time isn't considered a real thing but only an illusion experienced by grey zoners that drift unidirectionaly and involuntarily through layers
"True" Form
Our limited senses make us see some characters as they would like to be perceived. This is most well known with the Burgrr crew, who by default are portrayed in a more friendly way but they actually have a "true" form that is much more frightening. The reason why "true" is in quotations is because all interpretations are equally true.
Tubes
Used in referring to actual tubes or out-worldly things similar to tubes, they are mentioned a couple of times but are one of those things that we can't properly understand. They have quite the significance, as by considering tubes we can weaken a Glumdroodler.
Vibration
They are mostly what you would expect them to be, and most characters are very perceptive to them. By sensing vibrations (or something similar to them) they can feel subtle things we couldn't even understand, such as sensing when someone is infected by a reverberator and other such examples.
Worlds Within Worlds
Almost everything and everyone have worlds derived from them. The best examples are endozones, which are zones derived after living or dead bodies of creatures. The inhabitants of these worlds are derived from organisms found in the body and other elements from it (ex. antibodies, molecules, toxins, substances, etc), all with their own minds and lives. What happens to the body from the outside is directly reflected in the world derived from it, for example destroying the body destroys that world as well. Many inhabitants are derived from a multitude of organisms, as a single bacteria person can represent all bacteria of that species from the body. This logic also applies to the microorganisms, they each as well having their own endozones inhabited by organelles and so on infinitely. Even our world is derived from a bigger creature!
Zones
The separated "plane" of reality with its own rules and features. More info here.