Green’s Dictionary of Slang

hippie n.2

also hippy
[like many terms, hippie crossed from the black to white worlds; unlike most, however, it altered its meaning, in this case from negative to, in peer-group eyes at least, positive. Since the 1960s/early 1970s the negative image has returned, although not as a failed hipster but as a 1960s throwback]

1. (US black) one who poses (with little or no success) as a hipster n.

[US]D. Wallop Night Light 157: Man, I really get a bellyfull of these would be hippies.
C. Winick Antioch Rev. XXI:1 55: In many communities the ‘hippies’ who like to associate with jazzmen are drug users.
[US]T. Southern ‘You’re Too Hip, Baby’ in Southern (1973) 83: You’re too hip, baby. That’s right. You’re a hippy. [...] In fact, you’re what we might call a kind of professional nigger lover.
[UK]W. Manus Mott the Hoople 69: Leroy went off, diddledybopping along like the Harlem hippie he once was.

2. (orig. US) a sophisticated, cool, ‘hip’ person.

[US](con. 1948) G. Mandel Flee the Angry Strangers 385: Every junky and hippie came to sit round her table.
[US]L. Bruce How to Talk Dirty 93: The jazz muscians liked me. I was the only hippy around.
[US]W. King ‘The Game’ in King Black Short Story Anthol. (1972) 303: Always running down them spooks who ain’t into anything. Always forget to mention that the Rocks have hippies such as Sweet Mac.
[Aus]B. Oakley Salute to the Great McCarthy 158: Alby the Hippie intoning a slow Gregorian chant.

3. (orig. US, also hippiehead) a (usu.) young person, preaching a philosophy of ‘love and peace’, backed by a wide spectrum of drug usage, esp. of cannabis and hallucinogens.

[US]W. King ‘The Game’ in King Black Short Story Anthol. (1972) 303: All the hippies got a bag open.
[US]L. Wolf Voices from the Love Generation 278: hippiehead. A hippie.
[UK]Gandalf’s Garden 6 n.d. 11: hippy no precise informative is available on this elusive creature, which appears to be but a fabrication of the straight press to denote ordinary people with longish hair, beards and colourful clothes [...] Otherwise a hippy could be described as one who is hip, i.e. aware of the common unity of the Children of the Earth and seeks an easeful, happy life ‘doing his own thing’ in peace, without interference from grey-minded outside authorities.
[Can]R. Caron Go-Boy! 300: Sprawled on the hood of our hot car was a policeman disguised as a bearded hippy.
[UK]T. Wilkinson Down and Out 66: I met a gentle-faced man with hair like that of an Afghan hound, a hippie left over from the 1960s.
[UK]G. Burn Happy Like Murderers 49: All the first intake of lodgers were male; hippies or bikers, Hell’s Angels types.
[UK]I. Rankin Naming of the Dead (2007) 203: Not a bad bunch [...] for hippies, I mean.
[UK]K. Richards Life 227: It’s easy to bust a hippie.
[US]S. King Finders Keepers (2016) 83: Many kids made fun of him, calling him Ricky the Hippie because of the flower-power shirts and bell bottoms.

In compounds

hippie-flipping (n.)

(US drugs) using ‘magic’ mushrooms at the same time as MDMA.

[US]Newark Advocate (OH) 21 Oct. 5A/4: Hippie-flipping: combining mushrooms with Ecstasy.