MAT n.
An ornamental border made of paper, pasterboard, metal, etc., put under the glass which covers a framed picture; as, the mat of a daguerreotype. Mat grass. (Bot.) (a) A low, tufted, European grass (Nardus stricta). (b) Same as Matweed. -- Mat rush (Bot.), a kind of rush (Scirpus lacustris) used in England for making m…