Theologian: Has classical meaning, but only three saints are given the appellation Theologian: John the Theologian, Gregory the Theologian, and Symeon the New Theologian.
Confessor: one who has suffered for the faith but not martyred outright[1]
Enlightener: the saint who first brought the faith to a people or region, or who did major work of evangelization there
Equal-to-the-Apostles: one whose work greatly built up the Church, whether through direct missionary work or through assisting the Church's place in society[2]
Fool-for-Christ: a saint known for his apparent, yet holy insanity