The Collaborative International Dictionary of English v.0.48:

Epiphyte \Ep"i*phyte\, n. [Gr. 'epi` upon + fyto`n plant, ? to
   grow: cf. F. ['e]piphyte.]
   1. (Bot.) An air plant which grows on other plants, but does
      not derive its nourishment from them. See Air plant.
      [1913 Webster]

   2. (Med.) A vegetable parasite growing on the surface of the
      body. Epiphytic

WordNet (r) 3.0 (2006):

epiphyte
    n 1: plant that derives moisture and nutrients from the air and
         rain; usually grows on another plant but not parasitic on
         it [syn: air plant, epiphyte, aerophyte, epiphytic
         plant]