'Irreligion' definitions:

Definition of 'irreligion'

From: WordNet
noun
The quality of not being devout [syn: irreligiousness, irreligion]

Definition of 'Irreligion'

From: GCIDE
  • Irreligion \Ir`re*li"gion\, n. [L. irreligio: cf. F. irr['e]ligion. See In- not, and Religion.] The state of being irreligious; lack of religion; impiety. [1913 Webster]

Synonyms of 'irreligion'

From: Moby Thesaurus