<p><strong>noun</strong></p><ul><li>any plant, shrub, or tree belonging to the genus <em>Cassia</em>, of the legume family, having pinnate leaves and large clusters of flowers.</li><li>any of various cathartic drugs consisting of the dried leaflets of certain of these plants, as one drug Alexandrian senna derived from <em>C. acutifolia</em>, or another Tinnevelly senna derived from <em>C. angustifolia</em>.</li><li>wild senna.</li></ul>