Ambassador

Ambassador is a diplomat sent by a country to another country as official representative.

A promoter or representative is also sometimes referred to as ambassador, such as a brand ambassador, or ambassador for a specified event.

A quotation -
Ambassador is "an honest man sent to lie abroad for the commonwealth" (Wotton).

Nearby pages
Ambassador-at-large, Ambassadress, Ambato, Amber, Amber Alert, Amberger