/ Dictionary / Index O osteoarthritis: Meaning and Definition of Find definitions for: os•te•o•ar•thri•tis Pronunciation: (os"tē-ō-är-thrī'tis), [key] — n. Pathol. the most common form of arthritis, usually occurring after middle age, marked by chronic breakdown of cartilage in the joints leading to pain, stiffness, and swelling. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: osteoarthritis (Thesaurus) osteo- osteoarthrosis Related Content Daily Word Quiz: arid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language