A sitting duck
/ə ˌsɪtɪŋ ˈdʌk/informalUK · US
What does “A sitting duck” mean?
A sitting duck means an easy target with little protection
An unlocked bicycle left outside all night is a sitting duck for thieves. The danger comes from how little protection it has.
People can be sitting ducks too, including experienced people caught in a weak position. Calling someone this does not mean they deserve what happens.
When do people say it?
Use it for someone or something exposed to attack, criticism or exploitation. It emphasises vulnerability, not stupidity.
“An unlocked bike outside all night is a sitting duck for thieves.”
Is it formal or informal?
Register: informal. It is most at home in everyday conversation rather than formal writing. Most common in UK and US.
Where does it come from?
A duck sitting still is easier to hit than one in flight. The expression applies that picture to an exposed person or thing.
Origin confidence: Disputed; treat with caution
How do you say “A sitting duck” in other languages?
Last updated 2026-10-01