courtesy (n.) Look up courtesy at Dictionary.com
c. 1200, curteisie, "courtly ideals; chivalry, chivalrous conduct," also "a courteous act," from Old French curteisie (Modern French courtoisie), from curteis "courteous" (see courteous). From c. 1300 as "good will, kindness," also "a reward, a gift;" mid-14c. as "refinement, gentlemanly conduct." A specialized sense of curteisie is the source of English curtsy.