/ Dictionary / Index A acetaminophen: Meaning and Definition of Find definitions for: a•ce•ta•min•o•phen Pronunciation: (u-sē"tu-min'u-fun, as"i-tu-), [key] — n. Pharm. a crystalline substance, CHNO, used as a headache and pain reliever and to reduce fever. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: acetaminophen (Thesaurus) acetamide acetanilide Related Content Daily Word Quiz: fervor Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language