Cameo \Cam"e*o\, n.; pl. Cameos. [It cammeo; akin to F. cam['e]e, cama["i]eu, Sp. camafeo, LL. camaeus, camahutus; of unknown origin.]

A carving in relief, esp. one on a small scale used as a jewel for personal adornment, or like.

Note: Most cameos are carved in a material which has layers of different colors, such stones as the onyx and sardonyx, and various kinds of shells, being used.

Cameo conch (Zo["o]l.), a large, marine, univalve shell, esp. Cassis cameo, C. rua, and allied species, used for cutting cameos. See Quern conch.

Source: Webster's Revised Unabridged Dictionary (1913)