'chieftain' ultimately derives from Old French and Latin roots. The Old French element 'chef' came from Latin 'caput', where 'caput' meant 'head'.

'chieftain' passed into Middle English (forms such as 'chevetayn' / 'chevetain') from Old French and gradually evolved into the modern English form 'chieftain'.

Originally connected to the idea of 'head' or 'leader', the word's meaning developed into specifically denoting the leader of a tribe, clan, or similar group, which remains its primary sense today.