/ Dictionary / Index S submatrix: Meaning and Definition of Find definitions for: sub•ma•trix Pronunciation: (sub-mā'triks, -ma'triks), [key] — pl. -tri•ces -trix•es. a set of certain rows and columns of a given matrix. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. submarining submaxilla Related Content Daily Word Quiz: acquiesce Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language