governess (n.)

mid-15c., "female ruler," shortening of governouresse "a woman who rules" (late 14c.), from Old French governeresse "female ruler or administrator" (see governor + -ess). The Latin fem, form was gubernatrix. In the sense of "a female teacher in a private home" governess it is attested from 1712, probably as a fem. of governor in the now-obsolete sense "one who has charge of a young man's education and activities, a tutor" (1570s).