n. 1 a hist. a member of a radical democratic club established in Paris in 1789 in the old convent of the Jacobins (see sense 2). b any extreme radical. 2 archaic a Dominican friar. 3 (jacobin) a pigeon with reversed feathers on the back of its neck like a cowl. Jacobinic adj. Jacobinical adj. Jacobinism n.
[ orig. in sense 2 by assoc. with the Rue St Jacques in Paris: ME f. F f. med.L Jacobinus f. eccl.L Jacobus ]