Lewis & Short

incrēdŭlĭtas, ātis, f. [incredulus], disbelief, incredulity (post-class.).

  1. I. In gen., App. M. 1, p. 111, 18.
  2. II. Esp., religious disbelief, incredulity, Cod. Th. 16, 8, 19; Paul. Nol. Carm. 6, 95: venit ira Dei super filios incredulitatis, Vulg. Col. 3, 6 al.