a. A quadrilateral having two parallel sides.
b. Chiefly British A trapezium.
2. Anatomy A small bone in the wrist, situated near the base of the index finger.
3. Sports An area in the shape of a trapezoid marked behind the goal line and the goal in ice hockey, where the goalie is allowed to play the puck.
[Originally, a quadrilateral with no parallel sides (later confused with TRAPEZIUM, originally, a quadrilateral with two parallel sides), from New Latin trapezoīdēs, a quadrilateral with no parallel sides, from Late Greek trapezoeidēs, from Greek table-shaped : trapeza, table; see TRAPEZIUM + -oeidēs, -oid.]
trape·zoid′, trap′e·zoidal (-zoidl) adj.
(click for a larger image)trapezoid
The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2018 by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
The American Heritage Dictionary Blog
Check out our blog, updated regularly, for new words and revised definitions, interesting images from the 5th edition, discussions of usage, and more.