nullifidian
null·i·fid·i·an
Having no faith or religionHaving no faith or religion; atheist; also, doubtful or sceptical about faith or religion.
UK/ˌnʌ.lɪˈfɪd.i.ən/US/ˌnʌ.ləˈfɪd.i.ən/
Meaning
1 senses(not comparable)Having no faith or religion; atheist; also, doubtful or sceptical about faith or religion.
Near-synonym: agnostic