say it: REE-fleks
reflex is a noun and adjective meaning "an automatic instinctive unlearned reaction to a stimulus". It carries 2 recorded senses.
an automatic instinctive unlearned reaction to a stimulus
without volition or conscious control
“the automatic shrinking of the pupils of the eye in strong light”
“a reflex knee jerk”
“sneezing is reflexive”
physiology
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for reflex come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.