High·ness /ˈhaɪnəs/ noun [countableC] Your/Her/His Highness HIGH POSITION OR RANKused to speak to or about a royal person such as a prince or princess 殿下〔用于称呼或提到王子或公主〕Your/Her/His Highness• But that's the deal, Your Highness.• No, Your Highness, you are, of course, welcome to stay.• Besides, I don't want anything from you, Your Highness.