labrum

La"brum, n.; pl. L. Labra, E. Labrums. Etym: [L.] 1. A lip or edge, as of a basin. 2. (Zoöl.) (a) An organ in insects and crustaceans covering the upper part of the mouth, and serving as an upper lip. See Illust. of Hymenoptera. (b) The external margin of the aperture of a shell. See Univalve.

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