Top definition
In the days of sail, naval vessels mounted cannon carefully and purposefully rigged into positions which optimised the effect of their fire. Occasionally, the rigging of these very heavy guns might come loose, and with the vessel pitching about on high seas or during manuever in battle, the results for the ship and crew could prove catastrophic. The term has come to describe a person lacking prudence or insight, whose actions and/or speech jeopardises the safety of people in their proximity or under their authority.
Like a drunken bully, the politician shrugged off his advisors and taunted the insurgent forces operating in the country his armies were attempting to pacify. He had become a LOOSE CANNON.
by crowbone July 03, 2003
Get the mug
Get a loose cannon mug for your sister Jovana.
2
an individual who has little to no self control, does not think logically,whose grasp on reality is feeble. a seemingly misunderstood person who is in fact a walking disaster waiting to happen.
one loose cannon spoils the bunch.
by blockhead February 01, 2004
Get the mug
Get a loose cannon mug for your bunkmate Callisto.
3
A wild one. Someone who does not conform to the rest of society. A maverick. A guy who plays by his own rules and to hell with the consequences. Shows you what he can do.
JC - Ladies, let me show you what I can do.

Ladies - Wow. That John Clegg is one loose cannon.
by The Strut October 12, 2004
Get the mug
Get a loose cannon mug for your buddy Vivek.
5
1. Reiju Chacko
2. A danger and liability to all surrounding human beings.
After his 3rd cup of double back diamond coffee and 2 red bulls, Reiju Chacko is a loose cannon.
by The White Russian 007 October 21, 2011
Get the mug
Get a Loose Cannon mug for your mother-in-law Nathalie.
6
A term of jealous criticism applied to individuals of rare flexibility and creativity, by mobs of petty-minded group-thinking procedure slaves.
They called me a loose cannon until one of my crazy ideas saved them half a million bucks. After that I insisted on being called a 360 degree swivel-mounted artillery unit.
by Alex From Oz October 04, 2007
Get the mug
Get a loose cannon mug for your father-in-law Georges.
7
Bud 1: Did you hook up with Margo last night?
Bud 2: Easily, that girl is a fuckin' loose cannon.
by hoffmannb November 06, 2017
Get the mug
Get a loose cannon mug for your girlfriend Rihanna.