/ Dictionary / Index B brachio-: Meaning and Definition of Find definitions for: brachio- Pronunciation: [key] a combining form meaning “arm,” “upper arm,” used in the formation of compound words: brachiopod. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. brachiator brachiocephalic artery Related Content Daily Word Quiz: secular Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language