/thee"euh tin, -tuyn', -teen'/ , n.
1. a member of a congregation of regular clerics, founded in Italy in 1524 to combat Protestantism and promote higher morality among Roman Catholics.
2. a member of a congregation of nuns, founded in Italy in 1583 under the direction of the Theatine fathers.
[ 1590-1600; Theatenus of Chieti, Italy, where one of the founders held the archbishopric ]