Labrum

1. n. The external margin of the aperture of a shell. See Univalve.
2. n. A lip or edge, as of a basin.
3. n. An organ in insects and crustaceans covering the upper part of the mouth, and serving as an upper lip. See Illust. of Hymenoptera.

The word meanings were obtained from OPTED(The Online Plain Text English Dictionary), which is based on “The Project Gutenberg Etext of Webster’s Unabridged Dictionary” which is in turn based on the 1913 US Webster’s Unabridged Dictionary (See Project Gutenburg), as a text file.