embassage
noun
em·bas·sage ˈem-bə-sij 
1
: the message or commission entrusted to an ambassador
2
archaic : embassy
Word History
Etymology
variant (with em- after embassador "ambassador" and other derivatives based on Romance forms with em- em- replacing am-) of ambassage, probably alteration (by substitution of the suffix -age) of ambassade "embassy, message entrusted to an envoy" — more at embassy
First Known Use
circa 1530, in the meaning defined at sense 1