n. pl. cer·e·bel·lums or cer·e·bel·la (-bĕlə)
The trilobed structure of the brain, lying posterior to the pons and medulla oblongata and inferior to the occipital lobes of the cerebral hemispheres, that is responsible for the regulation and coordination of complex voluntary muscular movement as well as the maintenance of posture and balance.
[Medieval Latin, from Latin, diminutive of cerebrum, brain; see ker-1 in the Appendix of Indo-European roots.]
cer′e·bellar (-bĕlər) 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.