/ Dictionary / Index A alpha-naphthylthiourea: Meaning and Definition of Find definitions for: al•pha-naph•thyl•thi•o•u•re•a Pronunciation: (al"fu-naf"thil-thī"ō-yoo-rē'u, -yoor'ē-u, -nap"-), [key] — n. Chem. See Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. alpha-naphthyl group alphanumeric Related Content Daily Word Quiz: alacrity Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language