/ Dictionary / Index P pentyl group: Meaning and Definition of Find definitions for: pen'tyl group" Pronunciation: [key] — Chem. Chem. any of the univalent, isomeric groups having the formula CH–. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. pentylenetetrazol penuche Related Content Daily Word Quiz: feline Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language