Definition of Royal Highness in English:

Royal Highness

noun

  • An honorific title or form of address given to a person of royal rank.

verb

rare
  • with object To address (a person) by the title ‘(your) Royal Highness’.

Origin

Mid 16th century<br>early 19th century; earliest use found in Joseph Forsyth (1763–1815), writer on Italy.