'automechanism' originates from the combining form 'auto-' (from Greek 'autos' meaning 'self') + 'mechanism' (from Greek 'mēkhanē' meaning 'device, contrivance').

'mechanism' entered English via Latin and Old French from Greek 'mēkhanē'; the prefix 'auto-' is a Neoclassical combining form from Greek 'autos'. In modern English the two elements were combined to form 'automechanism'.

Initially the elements literally meant 'self' + 'device'; over time the compound has come to denote specifically a self-operating or self-regulating mechanism or process.