Atheos, pen cor mas. g. He that beleeueth no God: godlesse: a miscreant: an infidell.Atheroma pen. prod. huius atherómatis, pen. cor. neut. gen. Celsus. A little pushe or swelling in the necke, or vnder the atmes.
Lewis and Short: Latin dictionary
ăthĕŏs (-us), i, m., = a)/qeos, he that does not believe in God, an atheist: Diagoras, atheos qui dictus est, Cic. N. D. 1, 23, 63 B. and K. (Orelli writes it as Greek); so Arn. 3, p. 116; 5, p. 178.