/ Dictionary / Index U upside down: Meaning and Definition of Find definitions for: up'side down' Pronunciation: [key] with the upper part undermost. in or into complete disorder; topsy-turvy: The burglars turned the house upside down. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. upside upside-down cake Related Content Daily Word Quiz: inutiae Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language