n. pl. ac·e·tab·u·la (-lə)
1. Anatomy The cup-shaped cavity at the base of the hipbone into which the ball-shaped head of the femur fits.
2. Zoology A cavity or socket in the body of an insect into which an appendage fits.
3. Zoology A cup-shaped structure, such as the sucker of a tapeworm or leech.
[Latin acētābulum, vinegar cup, from acētum, vinegar; see ACETUM.]
ac′e·tabu·lar (-lər) adj.
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.