A person who does stupid things in an effort to get clout but rather gets hate. Fuck-nut could also be a term for someone you don't like.
Example 1
Man 1:did you hear ed, he jumped off a bridge to impress a girl
Man 2: I did. Ed is such a fuck-nut
Example 2:
KID: HEY HEY HEY
GIRL: SHUT UP I HATE YOU, YOU FUCK-NUT!
When you smoke so much weed that those little thoughts in the back of your head that are kind of anxiety inducing come straight to the front of your head like a goddamn bus like it'll have you be in paranoid of every little thing or you'll get so high that you don't feel well or you'll get so faded that you just pass the fuck out
Ex: yo, I took way too many hits off the pipe bro. I don't feel very good I think I'm greening out *passes out*