/ Dictionary / Index S seller's option: Meaning and Definition of Find definitions for: sell'er's op"tion Pronunciation: [key] (on the New York Stock Exchange) a special transaction that gives the seller the right to make late delivery of a security within a specified period, ranging from 5 to not more than 60 business days for stocks. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. sellers' market selling Related Content Daily Word Quiz: paradox Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language