Originally: the castor oil plant, Ricinus communis, a shrub native to the Mediterranean, eastern Africa, and parts of Asia and naturalized throughout…

Any of various trees and large shrubs having fruits or seeds that yield an oil; spec. †(a) an oleaster or olive tree (obsolete); (b) the castor oil…

Either of two plants with palmately lobed leaves: †(a) an unidentified medicinal herb, perhaps cut-leaved dead-nettle, Lamium hybridum (obsolete)…

= sense 1.

name for various plants having seeds resembling ticks, as †the castor-oil plant, Ricinus communis (obsolete), and the genera Coreopsis and Corispermum…

†(a) the castor-oil plant (see tick-seed n. above); (b) the American pennyroyal, Hedeoma pulegioides.

a terrestrial orchid, esp. one of the genus Orchis or Dactylorhiza, the roots of which were formerly used in medicine (cf. handed, adj. 2).

The castor-oil plant.

The castor-oil plant, Ricinus communis.

The castor oil plant, Ricinus communis; = Palma Christi, n. 1(b). In later use archaic (in biblical allusion).

More fully oil-nut tree. Any of various trees or shrubs that produce oil-rich nuts or large seeds; spec. (a) the castor oil plant, Ricinus communis…

Any of various kinds of seed that yield oil, e.g. sesame, linseed, flax seed, cotton-seed, niger seed, sunflower seed, etc.; (also) a plant or crop…

the bean or seed from which the oil is obtained; also, the castor-oil plant; cf. castor-bean, n.

The castor-oil bean. Cf. castor oil, n. compounds 1.

attributive, as in castor-oil plantor tree.