/ Dictionary / Index S subcrustal: Meaning and Definition of Find definitions for: sub•crus•tal Pronunciation: (sub-krus'tl), [key] — adj. Geol. situated or occurring below the crust of the earth. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. subcritical subculture 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