Duchess/ˈdʌtʃəs/ Definition 1 of 3Pro Tip 1/3Royal Titles Duchess is a specific title in the hierarchy of nobility, below queen. After the marriage, she became the Duchess of Sussex. Pro Tip 2/3Geographical Prefix Often 'duchess' appears with a place name representing the area of influence. The Duchess of Cornwall attended the charity event. Pro Tip 3/3Not Lady 'Duchess' is a higher rank than 'lady'; avoid confusing the terms. The Lady is the daughter; the Duchess, her mother.