/ Dictionary / Index H hemiacetal: Meaning and Definition of Find definitions for: hem•i•ac•e•tal Pronunciation: (hem"ē-as'i-tal"), [key] — n. any of the class of organic chemical compounds having the general formula RCH(OH)OR, where R is an organic group. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: hemiacetal (Thesaurus) -hemia hemialgia Related Content Daily Word Quiz: immense Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language