cour·te·san 
(kôrtĭ-zən)
(kôrtĭ-zən)n.
A woman prostitute, especially one whose clients are members of a royal court or men of high social standing.
[French courtisane, from Old French, from Old Italian cortigiana, feminine of cortigiano, courtier, from corte, court, from Latin cohors, cohort-; see gher-1 in the Appendix of Indo-European roots.]