'archduchess' originates from the prefix 'arch-' (from Greek 'arkhē', meaning 'chief, principal') combined with 'duchess' (from Old French 'duchesse', ultimately from Latin 'dux'/'ducis' meaning 'leader').

'archduchess' developed as the feminine counterpart to 'archduke' (influenced by German 'Erzherzog' and Middle Latin/Old French forms); the English formation combined the prefix 'arch-' with the established feminine title 'duchess' to form 'archduchess'.

Initially and historically it referred specifically to the wife, daughter, or female ruler associated with an archduke (not a general elevated noble); that core meaning has been retained in modern use.