Real Dictionary

M.A.T. in American English
Master of Arts in Teaching

mat
A mat of something such as grass or moss is a thick, untidy layer of it.
countable noun: A mat is a small piece of carpet or other thick material which is put on the floor for protection, decoration, or comfort.
countable noun: A mat is a small piece of something such as cloth, card, or plastic which you put on a table to protect it from plates or cups.

mat in American English 1
a flat, coarse fabric made of woven or plaited hemp, straw, rope, rushes, etc., often used as a floor covering
noun: a piece of fabric made of plaited or woven rushes, straw, hemp, or similar fiber, or of some other pliant material, as rubber, used as a protective covering on a floor or other surface, to wipe the shoes on, etc

mat in American English 2
matte2
to produce a dull finish on (metal, glass, etc.)
noun: a piece of cardboard or other material placed over or under a drawing, painting, photograph, etc., to serve as a frame or provide a border between the picture and the frame
transitive verb: to provide (a picture) with a mat

mat in American English 3
a matrix; printing mold

mat in American English 4
noun: the intaglio, usually of papiermâché, impressed from type or a cut, from which a stereotype plate is cast

mat in British English 1
noun: a thick flat piece of fabric used as a floor covering, a place to wipe one's shoes, etc

mat in British English 2
adjective: having a dull, lustreless, or roughened surface
noun: a border of cardboard, cloth, etc, placed around a picture to act as a frame or as a contrast between picture and frame
verb: to furnish (a picture) with a mat

mat in British English 3
noun

mat. in American English
matins

mat. in British English
abbreviation for: matinée

matinée in British English
noun: a daytime, esp afternoon, performance of a play, concert, etc