'Senna' definitions:

Definition of 'senna'

(from WordNet)
noun
Any of various plants of the genus Senna having pinnately compound leaves and showy usually yellow flowers; many are used medicinally

Definition of 'Senna'

From: GCIDE
  • Senna \Sen"na\, n. [Cf. It. & Sp. sena, Pg. sene, F. s['e]n['e]; all fr. Ar. san[=a].]
  • 1. (Med.) The leaves of several leguminous plants of the genus Cassia. (Cassia acutifolia, {Cassia angustifolia}, etc.). They constitute a valuable but nauseous cathartic medicine. [1913 Webster]
  • 2. (Bot.) The plants themselves, native to the East, but now cultivated largely in the south of Europe and in the West Indies. [1913 Webster]
  • Bladder senna. (Bot.) See under Bladder.
  • Wild senna (Bot.), the Cassia Marilandica, growing in the United States, the leaves of which are used medicinally, like those of the officinal senna. [1913 Webster]