/ Dictionary / Index A acetum: Meaning and Definition of Find definitions for: a•ce•tum Pronunciation: (u-sē'tum), [key] — n. a preparation having vinegar or dilute acetic acid as the solvent. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: acetum (Thesaurus) acetous acetyl Related Content Daily Word Quiz: gregarious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language