'Madwort' definitions:

Definition of 'madwort'

noun

Any garden plant of the genus Alyssum having clusters of small yellow or white flowers [syn: alyssum, madwort]

From: GCIDE

Madwort \Mad"wort`\, n. (Bot.) A genus of cruciferous plants (Alyssum) with white or yellow flowers and rounded pods. Alyssum maritimum is the commonly cultivated sweet alyssum, a fragrant white-flowered annual. [1913 Webster]