anesthesia
Multiple Entries:anesthesia anaesthesia
Concise Oxford English Dictionary © 2008 Oxford University Press:
anesthesia etc.
▶noun US spelling of anaesthesia etc.
Concise Oxford English Dictionary © 2008 Oxford University Press:
anaesthesia /ˌanɪsˈθiːzɪə/ (US anesthesia)
▶noun insensitivity to pain, especially as artificially induced by the administration of gases or drugs before a surgical operation.
– derivatives
anaesthesiologist noun,
anaesthesiology noun.
anaesthesiologist noun,
anaesthesiology noun.
– origin C18: mod. L., from Gk anaisthēsia, from an- ‘without’ + aisthēsis ‘sensation’.
'anesthesia' also found in these Oxford entries:

