Tra*pe"zi*um (?), n.; pl. E. Trapeziums (#), L. Trapezia (#). [NL., fr. Gr. a little table, an irregular four-sided figure, dim. of a table, for ; (see Tetra-) + foot, akin to foot; hence, originally, a table with four feet. See Foot.]
1. Geom.
A plane figure bounded by four right lines, of which no two are parallel.
2. Anat. (a)
A bone of the carpus at the base of the first metacarpal, or thumb.
(b)
A region on the ventral side of the brain, either just back of the pons Varolii, or, as in man, covered by the posterior extension of its transverse fibers.
© Webster 1913.