A shortening of bohemian used as slang. Can be used as a derogatory term as well.

The word Boho is liberally sprinkled through Tom Wolfe's 1968 Ken Kesey-driven opus The Electric Kool-Aid Test. The term is pretty much obsolete at this point, but it would be interesting to reintroduce it as the definition of bohemian itself has changed since 1968.