What is the X in X-mas?
Old English *kæcepol "tax-gatherer," from Old North French cachepol (Old French chacepol), from Medieval Latin cacepollus "a tax gatherer," literally "chase-chicken." For first element see chase (v.), for second see pullet. In lieu of taxes they would confiscate poultry. Later in English more specifically as "a sheriff's officer whose duty was to make arrests for debt." Cf. Old French chacipolerie "tax paid to a nobleman by his subjects allowing them and their families to shelter in his castle in wartime."