startle reaction is a noun meaning "a complicated involuntary reaction to a sudden unexpected stimulus (especially a loud noise); involves flexion of most skeletal muscles and a variety of visceral reactions". It carries one recorded sense.
a complicated involuntary reaction to a sudden unexpected stimulus (especially a loud noise); involves flexion of most skeletal muscles and a variety of visceral reactions
Definitions, synonyms and semantic relations for startle reaction come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.