/ Dictionary / Index P polyadenylic acid: Meaning and Definition of Find definitions for: pol'y•ad•e•nyl'ic ac'id Pronunciation: (pol'ē-ad"n-il'ik, pol"-), [key] — Biochem. Biochem. a homopolymer of adenylic acid enzymatically added to messenger RNA in eukaryotic cells to inhibit the hydrolytic breakdown of messenger RNA. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. polyadelphous polyalcohol Related Content Daily Word Quiz: modify Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language