\ ˈnē-ˌjərk How to pronounce knee-jerk (audio) , -ˈjərk \

Definition of knee-jerk

 (Entry 1 of 2)
: 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

Definition of knee jerk (Entry 2 of 2)
: an involuntary forward kick produced by a light blow on the tendon below the patella

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Synonyms & Antonyms for knee-jerk

Synonyms: Adjective

Antonyms: Adjective

  • nonmechanical
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Examples of knee-jerk in a Sentence

Recent Examples on the Web: Noun This transit can create confusion, and doesn't support knee jerk reactions. Venus Australis,, "Your Horoscope This Week," 19 Oct. 2020 My knee jerk reaction was to call the police and have Elenor call our neighbor friends a couple houses down. Marina Gomberg, The Salt Lake Tribune, "Marina Gomberg’s wife aches for her feisty mom, and realizes she very much lives within her," 25 Sep. 2020 The Narendra Modi government’s knee jerk decision to curtail ties with China overnight could cost India heavily. Niharika Sharma, Quartz India, "India will need to step up if it wants to avoid Chinese money for its infrastructure projects," 2 July 2020 The knee jerk reaction to provide ventilators for Africa is understandable. Efosa Ojomo, Quartz Africa, "African countries don’t need donated ventilators without revamping their health systems first," 2 May 2020 The knee jerk is, how could a team in UC’s precarious postseason position not try? Paul Daugherty,, "Doc's Morning Line: It's hard to believe the UC Bearcats can turn this around now," 2 Mar. 2020 But as with many of Trump's knee jerk proclamations, his threats satisfy short-term political goals but appear to contradict long-term concepts of US interests. Stephen Collinson, CNN, "Trump's threat to Iranian culture rekindles the 'madman' theory of international relations," 7 Jan. 2020 Analysts anticipate a knee jerk spike in crude oil prices when the market opens Monday. Dalvin Brown, USA TODAY, "Will the drone strikes in Saudi Arabia impact gas prices? Experts say yes.," 15 Sep. 2019 The fact that our knee jerk reaction to a woman becoming single is one of exhilarated empowerment rather than pity or dismay shows that minds have been changed, even slightly. Kathryn Lindsay,, "Why Be Engaged When You Can Be An Ex?," 13 July 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'knee-jerk.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of knee-jerk


1958, in the meaning defined above


1849, in the meaning defined above

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The first known use of knee-jerk was in 1849

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Cite this Entry

“Knee-jerk.” Dictionary, Merriam-Webster, Accessed 9 Mar. 2021.

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More Definitions for knee-jerk



English Language Learners Definition of knee-jerk

: occurring quickly and without thought
disapproving : often reacting quickly and without thought

knee jerk


Medical Definition of knee jerk

: 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

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