Madwort definitions
A low-growing plant (Asperugo procumbens) with small blue flowers, native to Eurasia and naturalized in North America.
noun
Origin of madwort
Sense 1, perhaps alteration (influenced by madder) of Dutch mede madder wort (from the use of A. procumbens to make a dye) Sense 2, originally a name for various plants supposed to cure rabies, and later also for plants of the genus Alyssum mad rabid wort (partial translation of Latin alyssum) (from Greek alusson alyssum)