(see: Word Report #1)
Superlinear Profits: something related to economies of scale, and the best argument against large corporations. Superlinear Profits is the notion of a business making a profit on an investment which is more than some fixed ratio × investment cost; more than linear in the cost. Examples include Big Data (having two data sets together produces more value than separately), any R&D and engineering (1 invention can turn into N products based on it), etc.
Irony Poisoning: see Jreg's video on it; what the Internet Sincerity initiative is meant to address.
Symbolic/Materialist/Impressionist narratives: whether a story is meant to be enjoyed for its symbolic meaning (such as an allegory to real world things), its concrete events (what happens to the characters, etc), or the aesthetic impression it produces upon its consumer, respectively.
Yow/Yee: meant to be a modern replacement for thou/thee: variants for the word "you" but explicitely singular and plural, respectively.
Realm Walker: a walking simulator video game specifically about exploring a strange realm, with a particular focus on ambiance and aesthetics. Includes Journey, NaissanceE, Fugue In Void, Peak Bleak Blues, Yume Nikki, and certainly others.
Mediagraphy: just discography or bibliography but for artists who produce media in a variety of formats. Particularly useful for artists whose work spans many mediums, like Jennifer Diane Reitz.
Very Culture: just an exclamation I enjoy making when faced with elements of the world I enjoy for their cultural value. Can apply to anything from borderers to Undertale.
Humancore vs Posthuman: an opposition between embracing the meatspace, "primal", even straight-up erroneous aspects of human existence; and ascending over those aspects to pursue what is percieved to be a higher, more intellectual existence. Note that Humancore is not the current memed "return to monkeh"; for central to Humancore is Culture, which is what is special about humans; though "return to monkeh" certainly is part of it.
(to) core value: (to) axiomatic(ally) value. An axiomatic value is something you ultimately care about, with no reason given or givable. If you value something for a reason, then it's the alternative: an instrumental value, and by asking what value it serves you eventually come down to axiomatic values.
Technology and Art: these may be standard terms, but I have my own definitions for them: technology is elements of culture that are instrumentally valued, and art is elements of culture that are intrinsically valued. If you engineer because you like beautiful works of engineering, not to get things done, that's art; if you create a video game whose purpose is to help people with trauma, that's technology.
While I'm at it, I'd like to challenge the notion that the term "literally" has lost its meaning and is now just a generic superlative. As I see it, this is not the case; the use of "literally" in cases where it doesn't mean exactly that is a figurative use of the word "literally", and indeed it has quite a distinctive semantic flavor from just a generic superlative.
(2020-11-18 edit: added the variant -ex to -plex)