In diplomatic usage, head of mission (HOM) or chief of mission (COM) from the French "chef de mission diplomatique" (CMD) is the head of a diplomatic representation, such as an
ambassador An ambassador is an official envoy, especially a high-ranking diplomat A diplomat (from grc, δίπλωμα; romanized Romanization or romanisation, in linguistics Linguistics is the scientific study of language A langua ...

, high commissioner,
nuncio An apostolic nuncio ( la, nuntius apostolicus; also known as a papal nuncio or simply as a nuncio) is an ecclesiastical {{Short pages monitor