The proof or trial, by chemical experiments, of the purity or fineness of metals,—particularly of the precious metals, gold and silver. A trial of weights and measures by a standard; as by the constituted authorities, clerks of markets, etc. Reg. Orig. 280. A trial or/examination of certain commodities, as bread, cloths, etc. Cowell; Blount.
—Assay office. The staff of persons by whom (or the building in which) the process of assaying gold and silver, required by government, incidental to maintaining the coinage, is conducted.