cou·ri·er 
(krē-ər, kûr-, kŭr-)
(krē-ər, kûr-, kŭr-)n.
1.
a. A messenger, especially one on official diplomatic business.
b. A spy carrying secret information.
2.
a. A personal attendant hired to make arrangements for a journey.
b. An employee of a travel agency serving as a guide for tourists.
[French courrier, from Old French, from Old Italian corriere, from correre, to run, from Latin currere; see kers- in the Appendix of Indo-European roots.]