Anesthesia is the deep medical sleep that lets you feel nothing during an operation. Under anesthesia, general anesthesia, local anesthesia.
Nobody fully knows how the general kind works — the drugs are used with great precision and the mechanism at the level of consciousness is still open. Before the 1840s surgery was done awake. This is the American spelling; British writing has anaesthesia.
1nounanesthesiaMedically produced loss of sensation or consciousness.
“The operation was done under anesthesia, so she felt nothing.”
anesthesia is a medical state.
Also accepted in games: anaesthesia, anesthetic
Greek anaisthesia means without sensation, from an-, not, plus aisthesis, feeling.
Ancient Greek
ἀναισθησία — without sensation
New Latin
anaesthēsia
English, today
anesthesia
Built from
Sense of “insensibility” attested since 1679, from New Latin anaesthēsia, from Ancient Greek ἀναισθησία (“without sensation”), from ἀν- (“not”) and αἴσθησις (“sensation”). by surface analysis, an- + -esthesia. Sense of “state induced by an agent” attested since 1846.
Etymology from Wiktionary, CC BY-SA