/ Dictionary / Index D double-O: Meaning and Definition of Find definitions for: dou•ble-O Pronunciation: (dub"ul ō'), [key] — pl. -Os. careful scrutiny or close inspection. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. double-nickel double occupancy Related Content Daily Word Quiz: languid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language