knee-jerk
adjectiveUK /ˈniː.dʒɜːk/
US /ˈniː.dʒɝːk/
Reacting very fast without thinking first.
His knee-jerk answer was to say no before he even heard the whole idea.
RELATED WORDS
OTHER MEANINGS
2. A sudden movement of the leg when the knee is tapped.
The doctor tapped her knee and watched for the knee-jerk.
3. Done or said as an immediate reaction rather than after careful thought.
The company made a knee-jerk decision to raise prices and later regretted it.
4. A response that happens without conscious control.
Sneezing is a knee-jerk reaction to dust in the air.