a member of a Roman Catholic religious order (the Society of Jesus) founded by Saint Ignatius Loyola in 1534 with the aims of defending the papacy and Catholicism against the Reformation and to undertake missionary work among the heathen
(sometimes not capital) (informal, offensive) a person given to subtle and equivocating arguments; casuist
1550, from Mod.L. Jesuita, member of the Society of Jesus, founded 1533 by Ignatius Loyola to combat Protestantism. Their enemies (in both Catholic and Protestant lands) accused them of belief that ends justify means, hence the sense "a dissembling person" (1640), and jesuitical "deceitful" (1613).