/ Dictionary / Index L loose cannon: Meaning and Definition of Find definitions for: loose' can'non Pronunciation: [key] a person whose reckless behavior endangers the efforts or welfare of others. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. loose loose end Related Content Daily Word Quiz: arboreal Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language