I. noun — [ mass noun] 1. insensitivity to pain, especially as artificially induced by the administration of gases or the injection of drugs before surgical operations. • during anaesthesia body temperature falls due to the effect of drugs.
• modern clinical anaesthesia uses low concentrations of volatile anaesthetics.
– origin early 18th cent.: modern Latin, from Greek anaisthēsia, from an- ‘without’ + aisthēsis ‘sensation’.