/ Dictionary / Index S superharden: Meaning and Definition of Find definitions for: su•per•hard•en Pronunciation: (s"pur-här'dn), [key] — v.t. Mil. harden (def. 6). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. supergravity superheat Related Content Daily Word Quiz: fidelity Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language