Atheistic; Atheistical

Part of speech: adjective (a.)

1. Pertaining to, implying, or containing, atheism; -- applied to things; as, atheistic doctrines, opinions, or books. Atheistical explications of natural effects. Barrow.

2. Disbelieving the existence of a God; impious; godless; -- applied to persons; as, an atheistic writer. -- A`the*is"tic*al*ly, adv. -- A`the*is"tic*al*ness, n.