Woad (?), n. [OE. wod, AS. wad; akin to D. weede, G. waid, OHG. weit, Dan. vaid, veid, Sw. veide, L. vitrum.] [Written also wad, and wade.]

1. Bot.

An herbaceous cruciferous plant (Isatis tinctoria). It was formerly cultivated for the blue coloring matter derived from its leaves.


A blue dyestuff, or coloring 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 It is now superseded by indigo, but is somewhat used with indigo as a ferment in dyeing.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. Milton.

Wild woad Bot., the weld (Reseda luteola). See Weld. -- Woad mill, a mill grinding and preparing woad.


© Webster 1913.