An organic acid (
C18H34O3) obtained from the castor-oil plant (
Ricinus communis, or
Palma Christi) and other species of the family
Euphorbiaceae; chemicaly it is d-12-hydroxyoleic acid (
CH3(CH2)5.CH(OH).CH2.CH=CH.(CH2)7COOH). Formerly called
palmic acid. [
1913 Webster]