Source : Webster's Revised Unabridged Dictionary (1913)

Hip \Hip\, n. [OE. hepe, AS. he['o]pe; cf. OHG. hiufo a bramble
   bush.] (Bot.)
   The fruit of a rosebush, especially of the English dog-rose
   ({Rosa canina}). [Written also {hop}, {hep}.]

   {Hip tree} (Bot.), the dog-rose.

Source : WordNet®

Rosa canina
     n : prickly wild rose with delicate pink or white scentless
         flowers; native to Europe [syn: {dog rose}]