Source : Webster's Revised Unabridged Dictionary (1913)

Melissa \Me*lis"sa\, n. [NL., fr. Gr. me`lissa a bee, honey.]
   (Bot.)
   A genus of labiate herbs, including the balm, or bee balm
   ({Melissa officinalis}).

Source : WordNet®

Melissa officinalis
     n : bushy perennial Old World mint having small white or
         yellowish flowers and fragrant lemon-flavored leaves; a
         garden escapee in northern Europe and North America [syn:
          {lemon balm}, {garden balm}, {sweet balm}, {bee balm}, {beebalm}]