Synonyms for Envoy (same or very similar meaning)
WordNet sense 1 (a diplomat having less authority than an ambassador):
envoy extraordinary, minister plenipotentiaryWordNet sense 2 (someone sent on a mission to represent the interests of someone else):
emissaryWordNet sense 3 (a brief stanza concluding certain forms of poetry):
envoiFrom the ODE community, based on WordNetadd/edit