Breadcrumb Home > Dictionary > Index S Cite stiffen: Meaning and Definition of Find definitions for: stiff•en Pronunciation: (stif'un), [key] — v.t. to make stiff. —v.i. to become stiff. to become suddenly tense, rigid, or taut, as in bracing oneself for or drawing back from shock, fear, or displeasure: He stiffened, expecting to hear the worst. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: stiffen (Thesaurus) stiff-arm stiffener TrendingHere are the facts and trivia that people are buzzing about. January 2021 Current Events: US News The Holocaust (1933–1945) Chinese New Year History, Meaning, and Celebrations Noble Titles and Ranks in a Monarchy The 5 Best Air Purifiers of 2020 Inaugural Trivia Related Content Daily Word Quiz: obviate Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language