1) Pretending to be something you are not, in hopes of fitting in, joining a group, or getting a job. ie: depicting wealth by wearing expensive clothes, shoes, handbags or driving fancy cars. Pretentious.
2) Using high vocab words so you can appear smart, in attempt to trick people into thinking you are educated..
Friend: "How do you expect to fit in with your boyfriends rich educated friends when you have a 10th grade education and make $5 an hour at WalMart".
Girl: "I've been reading the Dictionary to increase my vocabulary, bought some new designer clothes, a Louie Vuitton bag. You know, fake it till you make it!"