loose cannon

noun

1. a person whose reckless behavior endangers the efforts or welfare of others.

loose cannon

noun

1. a person or thing that appears to be beyond control and is potentially a source of unintentional damage

Word History and Origins

Origin of loose cannon¹

First recorded in 1975–80

Idioms and Phrases

One who is uncontrolled and therefore a serious and unpredictable danger. For example, We can't trust her to talk to the press—she's a loose cannon . This metaphoric expression alludes to cannon mounted on the deck of a sailing ship, which if dislodged during combat or a storm could cause serious damage to both vessel and crew by sliding about. Its figurative use dates from the first half of the 1900s.

Example Sentences

If you’re too much of a loose cannon, others can either just take you out or decide never to enter negotiations with you in the first place.

From Nautilus

Oh, and the company had a loose cannon liability in the driver’s seat in Elon Musk.

From Fortune

We tend to overestimate how much a politician like that can drag down their national party, but Greene’s lack of remorse and candor reinforces how much of a loose cannon she could be moving forward.

From Washington Post

As for the wife, she is a loose cannon, willing to sacrifice the people close to her to get what she wants.

From The Daily Beast

Cooper and Renner are solid as the loose cannon Richie and the upstanding Carmine, respectively.

From The Daily Beast

Churchill, on the contrary, they regarded with alarm, a loose cannon, a rogue elephant.

From The Daily Beast

When Diana called for an international ban, seven months before she died, a Tory minister accused her of being a "loose cannon".

From The Daily Beast

While some would be afraid to hire such a loose cannon, others see raw talent.

From The Daily Beast

A man reached the head of the ladder, stepped upon one of the loose cannon-balls and fell with an oath and a crash.

From Project Gutenberg

More About Loose Cannon

What does loose cannon mean?

A loose cannon is someone who behaves unpredictably and recklessly, often in a way that puts others at risk or negatively affects what they’re trying to do.

People considered loose cannons can’t be trusted because there’s no telling what they’re going to say or do. Loose cannons are thought to be uncontrollable. The metaphor is based on the image of a cannon on a ship that comes loose (such as during a storm) and starts dangerously sliding around and slamming into the people on board and the parts of the ship, causing injuries and damage.

Example: I need everyone on my team to be on the same page and to work together—I don’t want any loose cannons causing chaos.

Where does loose cannon come from?

he first records of the phrase loose cannon come from before the 1900s. The metaphor dates back to the time when wooden warships used to carry cannons, which were tied down to prevent them from shifting around as the ship moved. These cannons were big and heavy, and one coming loose would be very dangerous (mostly due to smashing into people and things, as opposed to exploding).

The phrase loose cannon is usually applied to the person in a group or on a team who’s unpredictable and whose unpredictability is likely to cause some kind of damage. Their recklessness may make it difficult for the team to accomplish its task, or it may derail the effort altogether. This recklessness can come in the form of erratic behavior, or it may come in the form of the incendiary things the loose cannon says.

The figurative sense of time bomb can refer to a person who’s likely to “explode” and cause some kind of chaos or damage. However, it’s most commonly used to refer to situations, as opposed to people. The figurative sense of powder keg is similar, but it always refers to potentially explosive situations.

Did you know ... ?

What are some words that share a root or word element with loose cannon? 

 

• loose
• cannon
• loose end
• loose change

What are some words that often get used in discussing loose cannon?

• unpredictable
• reckless
• erratic
• dangerous
• havoc
• chaos

How is loose cannon used in real life?

Calling someone a loose cannon is almost always intended as a criticism.

Sammy is a liability to his party we’ve all known that for a long time. But to be a liability to public health messaging is just too much. Why do they continually allow him to be such a loose cannon?

— ACullen (@cullen_annette) September 14, 2020

The old-fashioned number 10 was in so many cases a loose cannon off the field, enjoying a playboy lifestyle and an attitude to training that wouldn’t be tolerated in today’s sports science culture. pic.twitter.com/vQviD2ubDN

— Prashanth Nair (@reddevil07nair) July 29, 2020

Drafting in a 14-team keeper league with friends every year reminds me that I'm so much more comfortable drafting with industry "experts."

Loose cannons blow up drafts because you can't plan.

— Joe Dolan (@FG_Dolan) September 6, 2020

 

 

Try using loose cannon!

Which of the following words does NOT describe someone who’s considered a loose cannon?

A. dangerous
B. reckless
C. predictable
D. erratic