Definition of a suck-up?
Someone who tries really hard to be liked by someone (teacher: like being a tatle tale, parent, friend, etc) they would do almost anything to be liked by someone else, also this is my personal definition of the word.
Someone acting "favorable" for someone to gain an emotional, personal convincing powers over someone. Kinda like a tattle tail.
someone who just wants to get what they want. my brother does it all the time when i get home and tell him im in a bad mood. as soon as i say that he starts being all nice and stuff
some one that tries to do anything to get on your good side or to get something.