‖ labrum
(ˈleɪbrəm)
Pl. labra.
[L., cogn. w. labium.]
A lip or lip-like part. (Cf. labium.) a. In insects, crustaceans, etc.: A part forming the upper border or covering of the mouth. b. Conch. The outer lip of a univalve shell.
| 1816 T. Brown Elem. Conchol. 154 Labra, the lip. 1826 Kirby & Sp. Entomol. IV. 381 In the Ephemerina the parts of the mouth except the labrum and palpi appear to be mere rudiments. 1834 McMurtrie Cuvier's Anim. Kingd. 301 A mouth composed of a labrum, two mandibles, a ligula, and one or two pairs of jaws, and branchiæ. 1849 Murchison Siluria x. (1867) 237 [Pterygotus] The mouth..protected by a large heart-shaped labrum. 1851 Richardson Geol. viii. 240 The labrum, or outer lip..is the expansion, or continuation of the body of the shell, on the right margin of the aperture. 1880 Huxley Cray-Fish ii. 51 In front, the mouth is overlapped by a wide shield-shaped plate termed the upper lip or labrum. |