'autoclave' originates from French, specifically the word 'autoclave', where the prefix 'auto-' derives from Greek 'autos' meaning 'self' and 'clave' is related to Latin 'clavis' (key) or notions of 'shutting/sealing'.

'autoclave' was adopted into English from French in the late 19th century to denote a self-sealing or self-locking vessel; it later became specialized to mean a steam pressure vessel used for sterilization.

Initially it referred to a self-sealing/locking device or vessel; over time it evolved into the more specific modern meaning 'a pressure vessel used to sterilize by steam under pressure'.