/ Dictionary / Index A all-in-one: Meaning and Definition of Find definitions for: all-in-one Pronunciation: (ôl'in-wun'), [key] — n. an undergarment that combines a girdle and brassiere in one piece. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Allingham allision Related Content Daily Word Quiz: feline Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language