n. A plant of the genus Crocus.n. A genus of beautiful iridaceous plants, consisting of many hardy species, some of which are among the commonest ornaments of gardens.n. Saffron, obtained from plants of the genus Crocus. See saffron.n. A polishing-powder prepared from crystals of sulphate of iron, calcined in crucibles.n. In old chem., a yellowish or reddish impure oxid of some of the metals: as, crocus antimonii or crocus metallorum, an impure oxid of antimony obtained by deflagration of natural sulphid of antimony with saltpeter; crocus Martis, oxid of iron left on heating sulphate of iron to redness in the air; crocus Veneris, red oxid of copper obtained by heating copper in the air.