Night"shade` (?), n. [AS. nichtscadu.] (Bot.) A common name of many species of the genus Solanum, given esp. to the Solanum nigrum, or black nightshade, a low, branching weed with small white flowers and black berries reputed to be poisonous.

Deadly nightshade. Same as Belladonna (a). -- Enchanter's nightshade. See under Enchanter. -- Stinking nightshade. See Henbane. - - Three-leaved nightshade. See Trillium.