envoy (n.)

"messenger," 1660s, from French envoyé "messenger; a message; a sending; the postscript of a poem," literally "one sent" (12c.), noun use of past participle of envoyer "send," from Vulgar Latin *inviare "send on one's way," from Latin in "on" (from PIE root *en "in") + via "road" (see via (adv.)). The same French word was borrowed in Middle English as envoi in the sense "stanza of a poem 'sending it off' to find readers" (late 14c.).