knee-jerk
adjectiveUK /ˈniː.dʒɜːk/
US /ˈniː.dʒɝːk/
Reacting very fast without thinking first.
His knee-jerk answer was wrong because he didn't stop to think.
RELATED WORDS
OTHER MEANINGS
2. A sudden movement of the leg when the knee is tapped.
The doctor tapped my knee and got a quick knee-jerk.
3. A quick response made without careful thought.
Her complaint was just a knee-jerk to the bad news.
4. Happening by reflex rather than by choice.
Blinking is a knee-jerk action that protects your eyes.