emulsion

Short definition from Wiktionary

Noun

1. 1
   A stable suspension of small droplets of one liquid in another with which it is immiscible.
2. 2
   A colloid in which both phases are liquid.
3. 3
   The coating of photosensitive silver halide grains in a thin gelatine layer on a photographic film.

Verb

1. 1
   To paint with emulsion paint.