Definition of "matte"

(art, photography) A decorative border around a picture used to inset and center the contents of a frame.  examples

(film) A background, often painted or created with computers  examples

(pyrometallurgy) The molten metal sulfide phases typically formed during smelting of copper, nickel, and other base metals.  examples

(American spelling) Dull; not reflective of light.  examples