/ Dictionary / Index S substage: Meaning and Definition of Find definitions for: sub•stage Pronunciation: (sub'stāj"), [key] — n. the component part of a microscope below the stage, for supporting a condenser, mirror, or other accessories. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. subst. substance Related Content Daily Word Quiz: paradox Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language