- Pertaining to, implying, or containing, atheism; --
applied to things; as, atheistic doctrines, opinions, or books. - Disbelieving the existence of a God; impious; godless;
-- applied to persons; as, an atheistic writer.
Meaning of 'atheistical' (Princeton's WordNet)
1 . atheistical
[ a]
Meaning (1): - related to or characterized by or given to atheism