/ Dictionary / Index O outsert: Meaning and Definition of Find definitions for: out•sert Pronunciation: (out'sûrt"), [key] — n. Bookbinding. an additional folded signature or sheet into which another is bound. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. outsell outset Related Content Daily Word Quiz: vertigo Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language