Royal Highness: Meaning and Definition of

Roy'al High'ness

1. (in England)
1. a title used prior to 1917 and designating a brother, sister, child, grandchild, aunt, or uncle belonging to the male line of the royal family.
2. a title used since 1917 and designating a child or grandchild of the sovereign.
3. any person given this title by the Crown.
2. (in other countries) a person who is a member of a royal family.