Labrum \La"brum\, n.; pl. L. {Labra}, E. {Labrums}. [L.]
1. A lip or edge, as of a basin.
[1913 Webster]
2. (Zool.)
(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}.
[1913 Webster]