Anesthesia is a drug that numbs part of your body or makes you unconscious so that you don't experience pain during a procedure like surgery.
Anesthesia, pronounced "an-es-THEE-zhuh," comes from the Greek word anaisthetos, meaning "without sensation." There are two kinds of anesthesia: local anesthesia numbs just part of your body, like when a dentist numbs your mouth before filling a cavity. General anesthesia makes you unaware and free of all sensation, like when you are having your spleen removed.