A bone in the wrist at the base of the thumb. (noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "trapezium" in a sentence
"Rosse himself writing to Professor Nichol, in 1846, "I may safely say there can be little, if any, doubt as to the resolvability of the nebula; -- all about the trapezium is a mass of stars, the rest of the nebula also abounding with stars, and exhibiting the characteristics of resolvability strongly marked.""
"Orionis, also called the trapezium of Orion) is in itself the most striking multiple star in the whole heavens."
"But for better or worse, they thrived down here, especially in what is known as Cajun country, the geocultural trapezium whose points are New Orleans, Houma, Cameron, and Lafayette."