/ Dictionary / Index M mesothelioma: Meaning and Definition of Find definitions for: mes•o•the•li•o•ma Pronunciation: (mez"u-thē"lē-ō'mu, mes"-, mē'zu-, -su-), [key] — pl. -mas, -ma•ta a malignant tumor of the covering of the lung or the lining of the pleural and abdominal cavities, often associated with exposure to asbestos. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: mesothelioma (Thesaurus) mesosphere mesothelium Related Content Daily Word Quiz: panacea Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language