arch·duch·ess 
(ärch-dŭchĭs)
(ärch-dŭchĭs)n.
1. The wife or widow of an archduke.
2. A woman, especially an Austrian princess, holding an archduchy in her own right.
3. Used as a title for such a noblewoman.
[French archiduchesse, feminine of archiduc, archduke; see ARCHDUKE.]