/ Dictionary / Index R rhombencephalon: Meaning and Definition of Find definitions for: rhom•ben•ceph•a•lon Pronunciation: (rom"ben-sef'u-lon", -lun), [key] — pl. -lons, -la the hindbrain. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: rhombencephalon (Thesaurus) rhomb rhombic Related Content Daily Word Quiz: placid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language