rain tree noun4 •A tropical American tree (Albizia saman) having bipinnate leaves, globose clusters of flowers with crimson stamens, and sweet-pulp pods eaten by cattle, also used as an ornamental. •Philenoptera violacea (apple-leaf), native to Africa. •Brunfelsia spp. •Golden rain tree (Koelreuteria paniculata) formsrain trees · rain-trees