/ Dictionary / Index N naphthyl: Meaning and Definition of Find definitions for: naph•thyl Pronunciation: (naf'thil, nap'-), [key] — adj. Chem. containing the naphthyl group. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. naphthol naphthyl group Related Content Daily Word Quiz: banshee Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language