A person either boy or girl who changes they're looks and personality to fit in with another social clique. Like around one bunch of friends they will act emo and listen to depressing music and talk about how much their lives suck, but when they're around another bunch of friends they will act like a ganster listening to rap and wearing baggy pants and bling. Most 'posers' do not actually like the things they have to do to fit in, but they're are so set on being accepted they will do the things they are totally against. They also tend to copy other peoples styles then tell the person they copied it from that 'they made the style up'. Most people are posers because it's so damn hard to be an individual now-a-days (!). Oh and they also tend to label themselves a lot.
Poser: liek ZOMGZ im sooo scene!!!11!1 :3
Normal: Weren't you acting all ganster yesterday?
Poser: ewwzz nooo gansters are gayyy im liek totz scenie nowww <3333
Normal: okay lets change the conversation, whats you're favourite band?
Poser: MCR FTW! theyy so HxC <33 wats yuurs?
Normal: uhm i guess Greenday?
Poser: LOLOLOL POSERRR!!1!!
Normal: how am i a poser?
Poser: cuz they leik are soo punk and yu're all emooo!!