Source : Webster's Revised Unabridged Dictionary (1913)

Emulsion \E*mul"sion\, n. [From L. emulgere, emulsum: cf. F.
   ['e]mulsion. See {Emulge}.]
   Any liquid preparation of a color and consistency resembling
   milk; as:
   (a) In pharmacy, an extract of seeds, or a mixture of oil and
       water united by a mucilaginous substance.
   (b) In photography, a liquid preparation of collodion holding
       salt of silver, used in the photographic process.

Source : WordNet®

emulsion
     n 1: (chemistry) a colloid in which both phases are liquids; "an
          oil-in-water emulsion"
     2: a light-sensitive coating on paper or film; consists of fine
        grains of silver bromide suspended in a gelatin [syn: {photographic
        emulsion}]