a person, esp. of the late 1960s, who rejected established institutions and values and sought spontaneity, direct personal relations expressing love, and expanded consciousness, often expressed externally in the wearing of casual, folksy clothing and of beads, headbands, used garments, etc.

noun

beatnik , bohemian , drop-out , flower child , freak , free spirit , freethinker , yippie , longhair , rebel