knee jerk

¹ American  

noun

1. a reflex extension of the leg, caused by contraction of the quadriceps, resulting from a sharp tap on the patellar tendon; patellar reflex.

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knee-jerk ² American  

[nee-jurk] / ˈniˌdʒɜrk /

adjective

1. of or relating to a knee-jerk.

2. Informal. reacting according to a certain habitual manner; unthinking.

   a knee-jerk liberal.

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knee jerk British  

noun

1. Also called: patellar reflex.  physiol an outward reflex kick of the lower leg caused by a sharp tap on the quadriceps tendon just below the patella

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1. made or occurring as a predictable and automatic response, without thought

   kneejerk support

Etymology

Origin of knee jerk¹

First recorded in 1875–80

Origin of knee-jerk¹

First recorded in 1895–1900

Example Sentences

"Everyone recognizes there is a growing antibiotic resistance crisis, and the knee jerk reaction is to develop new antibiotics," You added.

From Science Daily

Unite's deputy regional secretary, Davy Thompson, said minimum service levels are "the most invidious example of knee jerk legislating this country has seen in a long time".

From BBC

“A sensible conversation is needed when balancing community safety with personal liberty. This is not a time for knee jerk responses,” he said.

From Seattle Times

"So we did have that sort of knee jerk over-reaction and it is something we have seen repeatedly in recent years here, sort of this triumph of hope over experience that markets keep going through."

From Reuters

In the past, Campbell said, India’s leaders have had “almost a knee jerk reaction” to resist such massive multilateral projects.

From Seattle Times