/ Dictionary / Index A arthro-: Meaning and Definition of Find definitions for: arthro- Pronunciation: [key] a combining form meaning “joint,” “jointed,” used in the formation of compound words: arthropod. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. arthritis Arthrobacter* 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