castor bean castor aralia • castor bean plant · · · Info · Definitions · Characters · · castor bean · · Text Common · · Latin · · Scripts 11 · · Length 3 · · Syllables Definitions · · · (noun) the toxic seed of the castor-oil plant; source of castor oil. Synonyms: castor bean. · · Noun Definition 1 Characters · · space U+0020 a latin small letter a U+0061 b latin small letter b U+0062 c latin small letter c U+0063 e latin small letter e U+0065 n latin small letter n U+006E o latin small letter o U+006F r latin small letter r U+0072 s latin small letter s U+0073 t latin small letter t U+0074