I. an ‧ aes ‧ the ‧ si ‧ a BrE AmE ( also anesthesia American English ) /ˌænəsˈθiːziə, ˌænɪsˈθiːziə $ -ʒə/ noun [uncountable]
1 . the use of anaesthetics in medicine
2 . the state of being unable to feel pain
II. an ‧ es ‧ the ‧ si ‧ a /ˌænəsˈθiːziə, ˌænɪsˈθiːziə $ -ʒə/ BrE AmE noun [uncountable]
[ Date: 1700-1800 ; Language: Modern Latin ; Origin: Greek anaisthesia , from aisthesis 'feeling' ]
the usual American spelling of ↑ anaesthesia