I. noun 1. a substance that induces insensitivity to pain. 2. [treated as sing.] ( anaesthetics) — the study or practice of anaesthesia. • he trained as a medical technical officer, working in anaesthetics.
II. adjective inducing or relating to insensitivity to pain. • anaesthetic drugs and gases.
– origin mid 19th cent.: from Greek anaisthētos ‘insensible’, related to anaisthēsia (see anaesthesia), + -ic.