1. noun
a) One whose occupation is to build with stone or brick; also, one who prepares stone for building purposes.
b) A member of the fraternity of Freemasons. See Freemason.
2. verb
To build stonework or brickwork about, under, in, over, etc.; to construct by masons; with a prepositional suffix; as, to mason up a well or terrace; to mason in a kettle or boiler.
Wikipedia foundation.