1A chair back resembling a yoke in shape, having a curved top rail with protruding ends; (also) the chair itself. Frequently attributive, especially in "yoke-back chair".
2A part of a garment shaped to fit over the back of the shoulders or around the back of the hips. Also: the rear side of a garment featuring such a part.
Mid 19th century; earliest use found in The Liverpool Mercury. From yoke + back.