/ Dictionary / Index S square sail: Meaning and Definition of Find definitions for: square' sail" Pronunciation: [key] — Naut. Naut. a sail set beneath a horizontal yard, the normal position of which, when not trimmed to the wind, is directly athwartships. See diag. under Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. square root square serif 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