courier (n.)

• bearer
• carrier
• cicerone
• commissionaire
• cowherd
• coxswain
• dragoman
• drover
• emissary
• envoy
• express
• go-between
• goatherd
• guide
• guidepost
• helmsman
• herd
• herdsman
• internuncio
• mercury
• messenger
• navigator
• nuncio
• pilot
• pointer
• post
• runner
• shepherd
• steerer
• steersman