hip (n.1) Look up hip at Dictionary.com
"part of the body where pelvis and thigh join," Old English hype "hip," from Proto-Germanic *hupiz (cognates: Dutch heup, German Hüfte, Gothic hups "hip"), from PIE *qeub- "to bend." Hip of a roof is from late 17c.
hip (n.2) Look up hip at Dictionary.com
"seed pod" (especially of wild rose), Old English heope, hiope "seed vessel of the wild rose," from Proto-Germanic *hiup- (cognates: dialectal Norwegian hjupa, Old Saxon hiopo, Dutch joop, Old High German hiafo, dialectal German Hiefe, Old English hiopa "briar, bramble").
hip (adj.) Look up hip at Dictionary.com
"informed," 1904, apparently originally in black slang, probably a variant of hep (1), with which it is identical in sense, though it is recorded four years earlier.
hip (interj.) Look up hip at Dictionary.com
exclamation used to introduce a united cheer (compare hip-hip-hurrah), 1827, earlier hep; compare German hepp, to animals a cry to attack game, to mobs a cry to attack Jews (see hep (2)); perhaps a natural sound (such as Latin eho, heus).