person: hey what's your favourite youtuber?
me: it's primink
person: oh what does he do? what's he like?
me: he's a commentary channel, he's a real twink
Mop is the ultimate Gen Z slang word. It can be a noun, verb (mopper), adjective (moppy), pronoun (mopper) and it can be anything.
So what is the definiton of it? There is none. The purpose of mop is for it to be used in any context and sentence and replace every other slang word.