principle of definitional equivalence - noun phrase - Often shortened to the ≡ symbol.  A polite way of saying "Because fuck you, that's why."  See also judgemental equality, homotopy type theory.

Q-hole - noun - A Nyquil hangover.

ablumeditation - verb - The act of taking a bath or shower to take a break from working on a problem, in the hope that insight will strike.

sharkfinning - verb, gerund - Learning something from scratch in an entirely hands-on way, which is to say, "Swimming with the sharks."  When you don't know what you're doing or how to do it, but you have a job to do.

Faraday roundtable - noun phrase - A meeting conducted entirely offline.  All portable devices and computers are powered down, and ideally locked inside conductive and grounded containers to prevent radio transmissions from reaching or being emitted from same.  Similarly, no active computers are permitted at the meeting.  The proceedings of such a meeting are carried out using Chatham house rules.

Named for the Faraday cage.

squirrel clever - noun complex - The state of being extremely smart when it comes to figuring out how to do something.  Notably, this does not include figuring out whether or not one should do something.