'autocephalic' originates from Greek, specifically from elements 'autós' and 'kephalē' (combined as 'autokephalikos'), where 'autós' meant 'self' and 'kephalē' meant 'head'.

'autokephalikos' in Greek passed into Late Latin/Medieval ecclesiastical usage and via Modern Latin/French forms contributed to English terms such as 'autocephalous' and the adjective 'autocephalic'.

Initially it literally meant 'self-headed' (i.e., 'having one's own head'); over time it came to mean 'self-governing' or 'independent', especially in an ecclesiastical/organizational sense.