from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A member of a group of politically radical hippies, active especially during the late 1960s.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A member of the Youth International Party, a group of politically active hippies.
- interj. Alternative form of yippee.
From Y(outh) I(nternational) P(arty) (influenced by hippie).(American Heritage® Dictionary of the English Language, Fourth Edition)