/ Dictionary / Index A atheroma: Meaning and Definition of Find definitions for: ath•er•o•ma Pronunciation: (ath"u-rō'mu), [key] — pl. -mas, -ma•ta a sebaceous cyst. a mass of yellowish fatty and cellular material that forms in and beneath the inner lining of the arterial walls. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: atheroma (Thesaurus) atherogenic atherosclerosis Related Content Daily Word Quiz: mamba Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language