Definition of woad:
- 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 It is now superseded by indigo, but is somewhat used with indigo as a ferment in dyeing.
- An herbaceous cruciferous plant ( Isatis tinctoria). It was formerly cultivated for the blue coloring matter derived from its leaves.
- "Experiments and Considerations Touching Colours (1664)", Robert Boyle.
- "Promenades of an Impressionist", James Huneker.
That crops of woad may be cut three times in the year, and that dyers' weed will change to green any cloth or silk first dyed blue with woad, " and for these uses there is great store of this herbe spent in all countries and thereof many fields are sowen for the purpose."- "The Old English Herbals", Eleanour Sinclair Rohde.