Noun

1. A teenager who imitated the Beatniks
2. One who chooses not to conform to prevailing social norms: especially one who ascribes to values or actions such as acceptance or self-practice of recreational drug use, liberal or radical sexual mores, advocacy of communal living, strong pacifism or anti-war sentiment, etc.
3. Someone with long hair: specifically, of a hair length that is considered unconventionally long in relation to one’s gender, age, ethnicity, or land of origin.
4. Someone who dresses in a hippie style.
5. One who is hip.

Adjective

1. Of or pertaining to hippies: e.g., “the hippie era”.
2. Not conforming to generally accepted standards: e.g., “Despite being for the widely-used Windows operating system, rather than using the commonly-used RAR or ZIP file-compression formats, they used a bunch of hippie compression formats instead”.