AFFINE

I. noun Etymology: Anglo-French affin, from Latin affinis, from affinis related Date: circa 1509 a relative by marriage ; in-law , II. adjective Etymology: Latin affinis, adjective Date: 1918 of, relating to, or being a transformation (as a translation, a rotation, or a uniform stretching) that carries straight lines into straight lines and parallel lines into parallel lines but may alter distance between points and angles between lines , ~ly adverb