Royal Highness

 Longman Dictionary of Contemporary English 5++朗文当代英语 5++LDOCE 5++朗文 5++ˌRoyal ˈHighness noun [countable]  your/his/her Royal Highness PGOused when speaking about or to a royal person, especially a prince or princess 殿下〔对王室成员尤其是王子或公主的称呼〕

Examples from the Corpus

Royal Highness• Her Royal Highness went round the room meeting many of those who had supported this Gala evening.• Her Royal Highness who was looking radiant, assured everybody that she would be back on skis at next year's Championships.• His Royal Highness was not available for comment, except in dire necessity.

ˌRoyal ˈHighness nounChineseSyllable  

a about royal used Corpus especially or to when person, speaking

Royal Highness
ˌRoyal ˈHighness noun [countable]
your/his/her Royal Highness used when speaking about or to a royal person, especially a prince or princess

Royal HighnessBrE /ˌrɔɪəl ˈhaɪnəs/ 🔊NAmE /ˌrɔɪəl ˈhaɪnəs/ 🔊 nounHis/Her/Your Royal Highness a title of respect used when talking to or about a member of the royal family （用作王室成员的尊称）殿下◆Their Royal Highnesses, the Duke and Duchess of Kent肯特公爵和公爵夫人殿下