/ Dictionary / Index P polyacrylonitrile: Meaning and Definition of Find definitions for: pol•y•ac•ry•lo•ni•trile Pronunciation: (pol"ē-ak"ru-lō-nī'tril, -trēl, -trīl), [key] — n. Chem. a polymer of acrylonitrile used in the manufacture of Orlon and other synthetic textiles. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. polyacrylic acid polyadelphous 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