/ Dictionary / Index O osteosarcoma: Meaning and Definition of Find definitions for: os•te•o•sar•co•ma Pronunciation: (os"tē-ō-sär-kō'mu), [key] — pl. -mas, -ma•ta a malignant tumor of the bone. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: osteosarcoma (Thesaurus) osteoradionecrosis osteosclerosis Related Content Daily Word Quiz: fabricate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language