convoy
convoy (kŏnʹvoi) noun
1. The act of accompanying or escorting, especially for protective purposes.
2. An accompanying and protecting force, as of ships or troops.
3. A group, as of ships or motor vehicles, traveling together with a protective escort or for safety or convenience.
verb, transitive
convoyed, convoying, convoys (kŏnʹvoi, kən-voiʹ)
To accompany, especially for protection; escort: warships convoying merchant vessels across the Atlantic.
[From Middle English convoyen, to escort, from Old French convoier, variant of conveier. See convey.]