/ Dictionary / Index S subsystem: Meaning and Definition of Find definitions for: sub•sys•tem Pronunciation: (sub'sis"tum, sub-sis'-), [key] — n. a secondary or subordinate system. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: subsystem (Thesaurus) subsurface subtangent Related Content Daily Word Quiz: neologism Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language