- a diplomatic official of the highest rank, sent by one sovereign or state to another as its resident representative (ambassador extraordinary and plenipotentiary).
- a diplomatic official of the highest rank sent by a government to represent it on a temporary mission, as for negotiating a treaty.
- a diplomatic official serving as permanent head of a country’s mission to the United Nations or some other international organization.
- an authorized messenger or representative. Abbreviation: Amb., amb.
- short for ambassador extraordinary and plenipotentiary; a diplomatic minister of the highest rank, accredited as permanent representative to another country or sovereign
- ambassador extraordinary a diplomatic minister of the highest rank sent on a special mission
- ambassador plenipotentiary a diplomatic minister of the first rank with treaty-signing powers
- ambassador-at-large US an ambassador with special duties who may be sent to more than one government
- an authorized representative or messenger
late 14c., also embassador, from Middle French ambassadeur, from Old French embassator, via Provençal or Old Spanish from Latin ambactus “a servant, vassal,” from Celtic amb(i)actos “a messenger, servant,” from PIE *ambhi- “about” (see ambi-) + *ag- “drive, lead” (see act (v.)). Cf. embassy. Forms in am- and em- were used indiscriminately 17c.-18c.