knee-jerk

1 of 2

adjective

ˈnē-ˌjərk 

-ˈjərk

: readily predictable : automatic

knee-jerk reactions

also, disapproving : reacting in a readily predictable way

The man was such a bleeding-heart knee-jerk liberal that you could predict the rest of the column after reading the first sentence.

—Andrew M. Greeley

knee jerk

2 of 2

noun

: an involuntary forward kick produced by a light blow on the tendon below the patella

Synonyms

Adjective

• automatic
• instinctive
• instinctual
• involuntary
• mechanic
• mechanical
• robotic
• spontaneous

Examples of knee-jerk in a Sentence

Adjective

a colleague known for her knee-jerk rejection of any proposal that she didn't originate

Recent Examples on the Web

Adjective

Most people don’t actually think this through when making knee-jerk reactions based on emotions. —Steve Booren, The Denver Post, 20 Oct. 2024

Most importantly, never let yourself be rushed into making a knee-jerk reaction, no matter how much urgency is injected into a conversation. —Davey Winder, Forbes, 13 Oct. 2024

Noun

The thing that keeps you from just acting out on your initial knee jerk reaction and from just acting impulsively. —Alaa Elassar, CNN, 24 July 2023

One of the most common knee jerk reactions is to move assets to cash. —Q.ai - Powering A Personal Wealth Movement, Forbes, 5 May 2023

Word History

First Known Use

Adjective

1958, in the meaning defined above

Noun

1849, in the meaning defined above

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Kids Definition

knee-jerk

1 of 2 adjective

ˈnē-ˌjərk

: readily predictable : automatic

a knee-jerk reaction to the proposal

knee jerk

2 of 2 noun

: an involuntary forward kick produced by a light blow on the tendon below the kneecap

Medical Definition

knee jerk

noun

: an involuntary forward jerk or kick produced by a light blow or sudden strain upon the patellar tendon of the knee that causes a reflex contraction of the quadriceps muscle

called also patellar reflex