Simp is someone who does way too much for a person they like or someone who decides to give all their attention to a girl and ditches their friends.
e.g Comic in rs3
female: Can i have gp pls?
Simp: Yeah no problem!
female: Thanks <3
Simp: its no problem
man or woman who is attracted to the receiving end but gaining nothing from it ps: we dont like simps
Simp originally meant a man doing almost anything to get a little bit of attention from a woman.
But weebs adopted this term and use it as liking a fictional character or being in love with a fictional character.
Some people just use it as finding a fictional character attractive.
1. "You're a simp for insert female twitch streamer here}."
2."Bro I'm such a simp for Gundham Tanaka,,"