/ Dictionary / Index S sign-off: Meaning and Definition of Find definitions for: sign-off Pronunciation: (sīn'ôf", -of"), [key] — n. the act or fact of signing off. personal approval or authorization; endorsement. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: sign-off (Thesaurus) sign of aggregation sign of the cross Related Content Daily Word Quiz: tenacious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language