/ Dictionary / Index S stiffener: Meaning and Definition of Find definitions for: stiff•en•er Pronunciation: (stif'u-nur, stif'nur), [key] — n. a person or thing that stiffens. any substance, as starch or buckram, that serves to stiffen fabric. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: stiffener (Thesaurus) stiffen stiff-necked Related Content Daily Word Quiz: procrastinate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language