noun. 
                    Lack of faith or belief in some religious system; especially, a lack of faith in, or disbelief of, the inspiration of the Scriptures, of the divine origin of Christianity.
                  
                
                  
                    noun. 
                    Unfaithfulness to the marriage vow or contract; violation of the marriage covenant by adultery.
                  
                
                  
                    noun. 
                    Breach of trust; unfaithfulness to a charge, or to moral obligation; treachery; deceit.