1. (Science: botany) An herbaceous cruciferous plant (isatis tinctoria). It was formerly cultivated for the blue colouring matter derived from its leaves.
2. A blue dyestuff, or colouring matter, consisting of the powdered and fermented leaves of the isatis tinctoria. It is now superseded by indigo, but is somewhat used with indigo as a ferment in dyeing. ”Their bodies . . . Painted with woad in sundry figures.
(Science: botany)” (milton) wild woad, the weld (reseda luteola). See Weld. Woad mill, a mill grinding and preparing woad.
Origin: OE. Wod, AS. Wad; akin to D. Weede, G. Waid, OHG. Weit, Dan. Vaid, veid, Sw. Veide, L. Vitrum
Alternative forms: wad, and wade.