'Baroness' definitions:

Definition of 'baroness'

From: WordNet
noun
A noblewoman who holds the rank of baron or who is the wife or widow of a baron

Definition of 'Baroness'

From: GCIDE
  • Baroness \Bar"on*ess\, n. A baron's wife; also, a lady who holds the baronial title in her own right; as, the Baroness Burdett-Coutts. [1913 Webster]