noun
( -es )
Etymology: Middle English heghnes, heynes, highnes, from Old English hēahnes, hēanes, from hēah high + -nes -ness — more at high
1. : the quality or state of being high : elevation , loftiness
the highness of a flooded river
2. : a person of honor — used as a title given to kings, princes, or other persons of exalted rank
His Royal Highness the Prince of Wales