'autoclave' originates from French, specifically the word 'autoclave', where 'auto-' meant 'self' and 'clave' meant 'key/lock' (ultimately from Latin 'clavis').

'autoclave' entered English from French in the late 19th century; the French form combined Greek-derived 'auto-' with a French/Latin element meaning 'key' or 'lock' to describe a self-locking or tightly closing vessel, and was later applied specifically to pressure vessels used for sterilization.

Initially, it referred to a 'self-locking' or tightly closing device; over time it became specialized to mean a sealed pressure vessel used especially for steam sterilization.