Ter·tul·lian 
(tər-tŭlyən, -tŭlē-ən) Originally Quintus Septimius Florens Tertullianus. AD 160?-230?
(tər-tŭlyən, -tŭlē-ən) Originally Quintus Septimius Florens Tertullianus. AD 160?-230? Carthaginian theologian who converted to Christianity (c. 193), broke with the Catholic Church (c. 207), and formed his own schismatic sect. His writings greatly influenced Western theology.