alyssum, n. [NL., fr. Gr. 'a`lysson, name of a plant, perh. fr. 'a priv. + ly`ssa raging madness.].
A genus of cruciferous plants; madwort. The sweet alyssum (Alyssum maritimum), cultivated for bouquets, bears small, white, sweet-scented flowers. [1913 Webster]