castor oil
(ˈkɑːstə, -æ-, ˈɔɪl)
[Origin of name uncertain: it has been suggested that this oil actually took the place of the drug castor, or perh. of oil of castor (see castor1 5), in use in midwifery, etc., and thus popularly assumed its name. So ‘castor oil pills’ is now a popular name for certain pills which have the same laxative effect but contain no castor oil.]
a. A pale yellow oil obtained from the seeds of Ricinus communis or Palma Christi (family Euphorbiaceæ), having a nauseous slightly acrid taste; used in medicine as a purgative, and in some parts of the world in lamps.
| 1746 P. Canvane (title), Dissertation on the Oleum Palmæ Christi..commonly called Castor Oil. 1799 Med. Jrnl. I. 468 A very useful medicine, where the stomach will bear it, is castor oil. 1803 Ibid. X. 492 His bowels to be kept open by castor oil. 1870 Yeats Nat. Hist. Comm. 205 Castor-oil is obtained by expression from the seeds without heat, hence it is called ‘cold-drawn castor oil’. |
| fig. 1873 Tristram Moab xv. 281 The canebrake tops..are ‘castor-oil to camels' stomachs’. |
b. attrib., as in
castor-oil plant or
castor oil tree;
castor-oil bean, the bean or seed from which the oil is obtained; also, the castor-oil plant;
cf. castor-bean.
| 1814 F. Pursh Flora Amer. Septentr. II. 603 Ricinus communis... Frequent in old plantations in Virginia and Carolina... Known by the name of Castor-oil Bean. 1845 Darwin Voy. Nat. xxi. (1852) 492 An occasional green castor-oil plant..may be met with. 1845 A. Wood Class-bk. Bot. ii. 336 R[icinus] communis... From its seeds is expressed the well known castor-oil of the shops..Castor-oil Bean. 1857 Livingstone Trav. xv. 272 The Palma-Christi, or castor-oil-plant. 1901 C. Mohr Plant Life Alabama 594 Ricinus communis. Castor Oil Bean. |