Someone who boasts about their accomplishments when in fact they have nothing to boast about or when a man is hitting on a woman and lies about how big his penis is or how good he is in bed.
Behaving in an attention-seeking manner via presenting oneself on the surface as being intelligent, provocative, important, avant-garde, humorous or significant, yet harboring ulterior motives, typically involving some form of personal gratification or material gain (e.g. advancement in social status, career, wealth, etc.).
Note that using this word is often conflated to be a pretentious act in and of itself, as this word is frequently used as a way to easily discredit people, works of art, ideas or statements while simultaneously boosting one's own status.
"I used to think they were a smart, edgy, fun group of people to hang out with... but as soon as they realized I didn't have anything to offer them in terms of getting more publicity or a book deal or an art gallery gig, they stopped talking to me. I don't even know why I try to be their friend anymore! Pretentious twits."
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Dude #1: "I really like the Three Stooges!"
Dude #2: "Whatever, they're so pretentious."
Dude #1: "Do you even know what that word means?"
A person obsessed with their sense of self worth. Characteristically they believe they are greater than other people and belittle others to gain status and feel powerful.
These people can almost never spell, drink too much, party with 'boiz' or are generally just stupid.
An annoying, usually psuedo-intellectual, skank or artist who listens to alternative music genres and thinks she's better than everyone. In order to maintain whatever self-esteem she has, she criticizes everyone and everything she sees, but in a very passive aggressive way, as to avoid open conflict. If she does fall into a verbal conflict her only defense mechanism is to rattle off random bullshit that makes no sense. Because her target doesn't know wtf she's talking about, she feels she is above the whole thing.