trapezium, n. [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.].
A plane figure bounded by four right lines, of which no two are parallel. [1913 Webster]
A bone of the carpus at the base of the first metacarpal, or thumb. [1913 Webster]