Florissant (flôr`ĭsənt, flŏ`–), city (1990 pop. 51,206), St. Louis co., E Mo., a suburb of St. Louis, on the Missouri River; inc. 1829. There is light manufacturing and limestone quarrying. The city was settled by French farmers and fur trappers c.1769, but the first civil government there was established in 1786 by the Spanish. The Spanish called the city San Ferdinand; its French name, fleurissant [flowering or flourishing], was adopted in 1939. Of interest are Old St. Ferdinand's Shrine and Convent (founded 1789; rebuilt 1820), and the historic French and Spanish homes, some dating from 1790. St. Louis Christian College and a Jesuit seminary are in the city.