chromatophore

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A pigment-containing or pigment-producing cell, especially in certain lizards, that by expansion or contraction can change the color of the skin. Also called pigment cell.
2. n. A specialized pigment-bearing organelle in certain photosynthetic bacteria and cyanobacteria.

Century Dictionary and Cyclopedia

1. n. One of the pigment-cells in animals.
2. n. In Actinozoa, one of the brightly colored beadlike bodies in the oral disk of some species, as Actinia mesembryanthemum. They are diverticula of the body-wall; their surface is composed of close-set bacilli, beneath which is a layer of strongly refracting spherules, then a layer of similarly refracting cones, subjacent to which are ganglion-cells and nerve-plexuses. These marginal bodies are supposed to be sense-organs.
3. n. In botany, a name that has been given to the granules which occur in the protoplasm of plants, including the colorless leucoplastids, the green chlorophyl granules or chloroplastids, and the chromoplastids.
4. n. One of the colored masses of protoplasm found in Protozoa. It may be either a living part of the cell, as in Mastigophora, or a symbiotic alga inhabiting the body of the protozoan. Calkins, Protozoa, p. 117.

Wiktionary

1. n. A pigment-bearing cell or structure found in certain fish, reptiles, cephalopods, and other animals.

GNU Webster's 1913

1. n. (Zoöl.) A contractile cell or vesicle containing liquid pigment and capable of changing its form or size, thus causing changes of color in the translucent skin of such animals as possess them. They are highly developed and numerous in the cephalopods.
2. n. (Bot.) One of the granules of protoplasm, which in mass give color to the part of the plant containing them.