knee-jerk
1 of 2adjective
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
Andrew M. Greeley knee jerk
2 of 2noun
: 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
See all Synonyms & Antonyms 
Example Sentences
Recent Examples on the Web Robert G. Eccles, Forbes, 3 June 2022 Instead of taking the knee jerk reaction of picking up your toys and going home. Laura Johnston, cleveland, 28 Feb. 2022 Despite the substantial losses the crypto market took over the weekend, King said the selloffs were merely a knee jerk reaction that happens from time to time, and not something to worry about in the long term. Fortune, 6 Dec. 2021 This transit can create confusion, and doesn't support knee jerk reactions. Venus Australis, refinery29.com, 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, 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, 2 July 2020 The knee jerk reaction to provide ventilators for Africa is understandable. Efosa Ojomo, Quartz Africa, 2 May 2020 The knee jerk is, how could a team in UC’s precarious postseason position not try? Paul Daugherty, Cincinnati.com, 2 Mar. 2020 See More
Noun
When the term was explained to the uninitiated, the knee jerk response was that paying attention to ESG (or certainly the E and S parts) was a way for companies and investors to lose money. Robert G. Eccles, Forbes, 3 June 2022 Instead of taking the knee jerk reaction of picking up your toys and going home. Laura Johnston, cleveland, 28 Feb. 2022 Despite the substantial losses the crypto market took over the weekend, King said the selloffs were merely a knee jerk reaction that happens from time to time, and not something to worry about in the long term. Fortune, 6 Dec. 2021 This transit can create confusion, and doesn't support knee jerk reactions. Venus Australis, refinery29.com, 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, 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, 2 July 2020 The knee jerk reaction to provide ventilators for Africa is understandable. Efosa Ojomo, Quartz Africa, 2 May 2020 The knee jerk is, how could a team in UC’s precarious postseason position not try? Paul Daugherty, Cincinnati.com, 2 Mar. 2020 See More Word History
First Known Use
Adjective
1958, in the meaning defined above
Noun
1849, in the meaning defined above
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
knee-jerk
adjective
as in automatic
done instantly and without conscious thought or decision a colleague known for her knee-jerk rejection of any proposal that she didn't originate Synonyms & Similar Words
Relevance
- automatic
- reflex
- mechanical
- instinctive
- spontaneous
- sudden
- robotic
- instinctual
- mechanic
- simple
- quick
- involuntary
- unwilling
- unreasoned
- reactive
- abrupt
- natural
- impulsive
- visceral
- unconscious
- conditioned
- casual
- inadvertent
- blind
- subliminal
- Pavlovian
- unintentional
- impromptu
- hasty
- rash
- random
- unintended
- unwitting
- mindless
- unforced
- impetuous
- unconsidered
- snap
- offhand
- improvised
- unprompted
- unpremeditated
- haphazard
- extemporaneous
- offhanded
- off-the-cuff
- ready
- unrehearsed
- unprepared
- unplanned
- spur-of-the-moment
- chance
- unstudied
- extempore
- chancy
- hit-or-miss
- ad-lib
Antonyms & Near Antonyms
- deliberate
- conscious
- voluntary
- wilful
- intentional
- willful
- volitional
- careful
- prepared
- intended
- thoughtful
- rehearsed
- calculated
- predetermined
- reasoned
- refined
- nonmechanical
- designed
- cultivated
- willed
- projected
- meticulous
- foresighted
- measured
- aforethought
- advised
- considered
- studied
- forethoughtful