FWIW, I don't even really feel like the "legal definition" is relevant: a lot of people on Hacker News seem to think the only thing that matters is the law, and

FWIW, I don't even really feel like the "legal definition" is relevant: a lot of people on Hacker News seem to think the only thing that matters is the law, and then attempt to move every conversation into whether the law says one thing or the other, and yet fraud is a concept that no one has ever questioned exists even when the law isn't in question or involved. The definition from Oxford Languages (the one Google pulls from) has an "or criminal", but that's clearly elidable, so "wrongful deception intended to result in financial or personal gain" is what we are left with, and the question is then just whether or not it is "wrongful"... and frankly, you're going to end up there also, because I'm pretty sure the person you are arguing with is going to say "this isn't lying". I guess what I mean to say is: you are actually trying to have an ethical argument, but are being drawn into a silly semantic argument over the definition and source of a word you used not really because the definition matters but because it has a bad connotation and since they disagree that this is unethical behavior they want a happy word there, when the real problem is the ethical disagreement.