anesthesia

n. (Pathology) lack of feeling, loss of sensation (caused by disease); (Medicine) localized or general reduction of sensitivity to pain (through drugs)

Anesthesia or anaesthesia (see spelling differences; from Greek αν- an- “without” + αἲσθησις aisthesis “sensation”) has traditionally meant the condition of having the feeling of pain and other sensations blocked. This allows patients to undergo surgery and other procedures without the distress and pain they would otherwise experience. The word was coined by Oliver Wendell Holmes, Sr. in 1846. Another definition is a "reversible lack of awareness", whether this is a total lack of awareness (e.g. a general anaesthestic) or a lack of awareness of a part of a the body such as a spinal anaesthetic or another nerve block would cause.
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Anesthesia /an·es·the·sia/ 1. loss of sensation, usually by damage to a nerve or receptor. 2. loss of the ability to feel pain, caused by [more]Anesthesia - Community and Resources

Noun
1. loss of bodily sensation with or without loss of consciousness
(synonym) anaesthesia
(hypernym) physiological state, physiological condition
(hyponym) cryoanesthesia, cryoanaesthesia

v. anesthetise