cameo

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A gem or shell carved in relief, especially one in which the raised design and the background consist of layers of contrasting colors.
2. n. The technique of carving in this way.
3. n. A medallion with a profile cut in raised relief.
4. n. A brief vivid portrayal or depiction: a literary cameo.
5. n. A brief appearance of a prominent actor, as in a single scene of a motion picture. Also called cameo role.
6. v. To make into or like a gem or shell carved in relief.
7. v. To portray in sharp, delicate relief, as in a literary composition.
8. v. To make a brief appearance, as in a film: She cameoed as Anne Boleyn in A Man for All Seasons.

Century Dictionary and Cyclopedia

1. n. An engraving in relief upon a gem, a hard stone of moderate size, or a similar material, or the object itself so engraved, as distinguished from an intaglio; specifically, such an engraving upon a stone or a shell having two or three layers differing in color, such as an onyx, agate, etc., and so treated as to utilize the effect of the variety of coloring. Cameos on stone are called stone cameos, in contradistinction to the shell cameos, or those cut on shells which have superposed layers varying in color, such as the Cassis rufa, which gives red on sardonyx, the Cassis madagascariensis, white on dark claret, the Cassis cornuta, white on orange, the Strombus gigas, white on pink, and other tropical shells. Cameos in distinct bands of colors have been produced since about 150 b. c.; and some of the ancient examples, as the Sainte Chapelle agate, in Paris (13 by 11 inches), representing the apotheosis of Augustus, and the Vienna onyx (9 by 8 inches), representing allegorically the coronation of Augustus, surpass in size and in delicacy of execution the best modern specimens.
2. n. Hence Raised or anaglyphic work in art on a miniature scale; specifically, the art of engraving small figures in relief: opposed to intaglio: as, a stone or shell cut in cameo; a vase ornamented in cameo.

Wiktionary

1. n. A piece of jewelry, etc., carved in relief.
2. n. A single very brief appearance by a prominent celebrity in a movie or song.
3. v. To appear in a cameo role.

GNU Webster's 1913

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

WordNet 3.0

1. n. engraving or carving in low relief on a stone (as in a brooch or ring)