A person, usually in their 20s, who likes indie music, alternative lifestyles, indie films, riding fixed gear bikes, and hanging out in bars and other places you probably never heard of.
An actual hipster doesn't go around saying things like "I'm so hipster" or "I'm such a hipster" because hipster isn't a thing to be or a subculture, a hipster just is, despite people who say hipsters spend their time trying composing their whole persona. Most don't.
Hipsters are not scene kids, as the generally don't listen to overly emotional music by scremo bands, they usually tend to listen to music by boring bands, mature bands, and experimental stuff. Even though the music can suck, it tops scene kid music any day.
Hipster style is usually outlandish, but ranges to plain an no flashy. Thick rim glasses, usually darker(not goth or emo dark) or earth tone clothes. Normalized colors, but outlandish way of dressing.
A hipster do not have wild hair, people get them confused with scene kids, hipsters usually wear hair that's less outlandish that scene kids, and they usually sport one solid color, unlike scene kids. And while they do, their hair still seems dirty, and less composed.
They also like vintage things, music, clothing items, video games, photographing, books, and even homes, vintage is a plus for hipsters.
Williamsburg New-York is fucking hipsters paradise. They're gentrifying Bedstuy by the day.