1) Flour producer 2) Grinder 3) Mill 4) Old-time factory 
A gristmill (also: grist mill, corn mill or flour mill) grinds grain into flour. The term can refer to both the grinding mechanism and the building that holds it. ==History== ===Early history=== The Greek geographer Strabo reports in his Geography a water-powered grain-mill to have existed near the palace of king Mithradates VI Eupator at Cabira, ...
• (n.) A mill for grinding grain; especially, a mill for grinding grists, or portions of grain brought by different customers; a custom mill.
Grist'mill' noun A mill for grinding grain; especially, a mill for grinding grists, or portions of grain brought by different customers; a custom mill. 
[n] - a mill for grinding grain (especially the customer`s own grain)
noun a mill for grinding grain (especially the customer`s own grain)