/ Dictionary / Index S square serif: Meaning and Definition of Find definitions for: square' ser'if Pronunciation: [key] — Typography. Typography. a font of type having serifs with a weight equal to or greater than that of the main strokes. Cf.(def. 5). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. square sail square set Related Content Daily Word Quiz: deleterious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language