What is a title of honor given to certain high dignitaries, esp. to viceroys, ministers, and ambassadors, to English colonial governors, etc. It was formerly sometimes given to kings and princes called?

excellency — A title of honor given to certain high dignitaries, esp. to viceroys, ministers, and ambassadors, to English colonial governors, etc. It was formerly sometimes given to kings and princes. (Webster's 1913.)

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