How do you say “A loose cannon” in French?
The closest natural French equivalent is une personne incontrôlable, which literally means “an uncontrollable person”. English speakers use a loose cannon to mean an unpredictable person whose uncontrolled actions may cause problems for others. Keep the risk clear by saying what the person might do wrong. Register: neutral. Usage frequency: common.
Closest natural French
une personne incontrôlable
/yn pɛʁsɔn ɛ̃kɔ̃tʁolabl/
- Literal meaning
- “an uncontrollable person”
- Register
- neutral
- How often it's used
- common
- Equivalence
Close equivalent
85 out of 100
What a native French speaker would actually say
“Incontrôlable” describes someone who is hard to control. To keep the English sense of risk, say what they might do: damage negotiations, for example, or make promises without asking.
“Un élément imprévisible” is useful when discussing a team. Simply calling someone independent would lose the criticism in “loose cannon.”
How close is the meaning?
- Meaning4 out of 5
- Tone4 out of 5
- Context5 out of 5
- Literal similarity1 out of 5
These ratings are editorial approximations, not measurements.
What are other ways to say it in French?
un élément imprévisible
Literally: “an unpredictable element”
Useful in a team or organisation; less directly accusatory.
Common translation traps
un électron libre
This can praise someone's independence. It does not necessarily suggest they might cause trouble.
The notes above explain why these versions do not work in this context in French.
In context
English
He's a loose cannon who may damage the negotiations.
French
C'est une personne incontrôlable qui risque de compromettre les négociations.
English
The team considers her a loose cannon.
French
L'équipe la considère comme un élément imprévisible et difficile à maîtriser.
Related expressions
- What “A loose cannon” means in English
- Rock the boat, Cause trouble or disrupt a stable situation.
- Get out of hand, To become uncontrolled or wild
Last updated 2026-09-16