the GNU version of the Collaborative International Dictionary of English
adj. Having or existing in three different phases of color; having three distinct color varieties; -- said of certain birds and insects.
The Century Dictionary and Cyclopedia
Characterized by three colors; in a specific sense, having the three fundamental color-sensations of red, green, and purple, as the normal eye, in distinction from a color-blind eye, which can perceive only two of the fundamental colors.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
adj. having or involving three colors
Word Usage
"In addition, while we base our 'trichromatic' color combinations on red, blue, and green, bees base their colors on UV, blue, and green a much richer type of light."