The Collaborative International Dictionary of English v.0.48:
Diplomat \Dip"lo*mat\, Diplomate \Dip"lo*mate\, n. [F. diplomate.] A diplomatist. [1913 Webster]WordNet (r) 3.0 (2006):
diplomat n 1: an official engaged in international negotiations [syn: diplomat, diplomatist] 2: a person who deals tactfully with others