'Duchess' definitions:

Definition of 'duchess'

From: WordNet
noun
The wife of a duke or a woman holding ducal title in her own right

Definition of 'Duchess'

From: GCIDE
  • Duchess \Duch"ess\, n. [F. duchesse, fr. duc duke.] The wife or widow of a duke; also, a lady who has the sovereignty of a duchy in her own right. [1913 Webster]