Educational institution, usually for training in theology. In the U.S. the term was formerly also used to refer to institutions of higher learning for women, often teachers' colleges. Since at least the 4th century there have been seminaries for the training of clergy. The first known group of seminarians was gathered by St. Basil of Ancyra. The term dropped out of general use in the Middle Ages, when most theological training was in monasteries, and later, in the universities. After the Reformation and the emergence of new denominations, seminaries again came into use, especially in the U.S. The 16th-century Council of Trent ordered seminaries to be opened in every diocese.