\hip-stur\n. One who possesses tastes, social attitudes, and opinions deemed cool by the cool. (Note: it is no longer recommended that one use the term "cool"; a Hipster would instead say "deck.") The Hipster walks among the masses in daily life but is not a part of them and shuns or reduces to kitsch anything held dear by the mainstream. A Hipster ideally possesses no more than 2% body fat.
-The Hipster Handbook, Robert Lanham
Typically a Hipster can be identified by vintage or thrift-store bougt clothing, a taste for obscure or underground music, a penchant for irony and an elitist attitude.