Word Origin & History
O.E. curs "a prayer that evil or harm befall one," of uncertain origin, perhaps O.Fr. curuz "anger," or L. cursus "course." Connection with cross is unlikely. No similar word exists in Gmc., Romance, or Celtic. Meaning "to swear profanely" is from c.1230. Curses as a histrionic exclamation is from 1885.
The curse "menstruation" is from 1930.