/ Dictionary / Index A abomasum: Meaning and Definition of Find definitions for: ab•o•ma•sum Pronunciation: (ab"u-mā'sum), [key] — pl. -sa the fourth or true stomach of cud-chewing animals, lying next to the omasum. See diag. under Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: abomasum (Thesaurus) abolla abomasus Related Content Daily Word Quiz: paradox Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language