Phrase guide

knee-jerk reaction

noun · 1 senses · updated from the 2026-07-25 local source snapshot

Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.

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Pronunciation

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noun

Meaning 1

An instantaneous reaction made without thought.

Definition source: English Wiktionary via Wiktextract

Usage: idiomatic

Examples

Near-synonym: gut reaction

Meaning relationships

Synonyms: gut reaction

Antonyms: none provided

History

Etymology

By means of an elliptical reference to the reflexes of reflex arcs, in this case the patellar reflex.

Word forms

Inflections and variants

knee-jerk reactions — plural

Word family

Derived and related words

Derived: none provided

Related: kneejerk reflex

Semantic map

Other relationships

Sources

Where this information comes from

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