To act like you are something so you can, in fact, become that thing.
I had no idea her parents were white trash as she always acted so classy. Fake it till you make it!
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!"
excitement about a task or project. Usually used in military slang.
"Man we gotta give a tour to the general and act like we like it. guess we gotta fake it till you make it."