'autoclave' originates from French, specifically the word 'autoclave,' formed from Greek 'auto-' meaning 'self' plus a form related to Latin 'clavis' (via French) meaning 'key' or 'lock'.

'autoclave' entered English from French in the late 19th century as 'autoclave' and was adopted with the same spelling and sense referring to a self-sealing pressure vessel.

Initially it denoted a 'self-sealing' or 'self-locking' vessel; over time it came to refer specifically to a pressure vessel used for sterilization by steam, and now commonly means the sterilization process or the device itself.