the GNU version of the Collaborative International Dictionary of English
n. 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.
The Century Dictionary and Cyclopedia
n. A plant of the genus Alyssum.
n. [As if a contraction of madderwort, having been used as a substitute for madder.] A plant of the borage family, Asperugo proeumbens, whose root was used like madder: commonly called German madwort.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. any garden plant of the genus Alyssum having clusters of small yellow or white flowers