[cou.ri.er] n [MF courrier, fr. OIt corriere, fr. correre to run, fr. L currere] (1579) 1: messenger: as a: a member of a diplomatic service entrusted with bearing messages b (1): an espionage agent transferring secret information (2): a runner of contraband c: a member of the armed services whose duties include carrying mail, information, or supplies
2: a traveler's paid attendant; esp: a tourists' guide employed by a travel agency