irreverent in WordNet English dictionary

1. not revering god
   godless  irreverent 
   
2. characterized by a lightly pert and exuberant quality
   "a certain irreverent gaiety and ease of manner"
   impertinent  irreverent  pert  saucy 
   
3. showing lack of due respect or veneration
   "irreverent scholars mocking sacred things"; "noisy irreverent tourists"
   irreverent