[tra.pe.zi.um] n, pl -zi.ums or -zia [NL, fr. Gk trapezion, lit., small table, dim. of trapeza table, fr. tra- four (akin to tettares four) + peza foot; akin to Gk pod-, pous foot--more at four, foot] (1570) 1 a: a quadrilateral having no two sides parallel b Brit: trapezoid 1b
2: a bone in the wrist at the base of the thumb