'autoclave' originates from French, specifically the word 'autoclave', where 'auto-' meant 'self' (from Greek 'autos') and 'clave' meant 'locking/bolt' (from Latin root related to 'clavis' meaning 'key' or 'lock').

'autoclave' entered English in the late 19th century from French 'autoclave' (coined to describe a self-sealing/locking vessel) and became established in technical English to denote a pressure vessel used for sterilization.

Initially, it meant 'a self-locking or self-sealing vessel', but over time it evolved into its current meaning of 'a pressure chamber used to sterilize equipment and materials (especially by steam at high pressure)'.