The Collaborative International Dictionary of English v.0.48:

Religiosity \Re*lig`i*os"i*ty\ (-l?j`?-?s"?-t?), n. [L.
   religiositas: cf. F. religiosit?.]
   The quality of being religious; religious feeling or
   sentiment; religiousness. [R.] --M. Arnold.
   [1913 Webster]

WordNet (r) 3.0 (2006):

religiosity
    n 1: exaggerated or affected piety and religious zeal [syn:
         religiosity, religionism, religiousism, pietism]