anything used to support the head of a person when reposing; especially, a sack or case filled with feathers, down, hair, or other soft material.-a piece of metal or wood, forming a support to equalize pressure; a brass; a pillow block.-a block under the inner end of a bowsprit.-a kind of plain, coarse fustian.-to rest or lay upon, or as upon, a pillow; to support; as, to pillow the head.