/ Dictionary / Index A aortic valve: Meaning and Definition of Find definitions for: aor'tic valve' Pronunciation: [key] — Anat. Anat. a semilunar valve between the aorta and the left ventricle of the heart that prevents the blood from flowing back into the left ventricle. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. aortic stenosis aortitis Related Content Daily Word Quiz: penchant Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language