atheism
n.
1580s, from French athéisme (16c.), from Greek atheos "without god" (see atheist). A slightly earlier form is represented by atheonism (1530s) which is perhaps from Italian atheo "atheist." Ancient Greek atheotes meant "ungodliness."
〔李〕[a-=without 无；the=god 神；-ism=the belief 信仰→] n. the belief that there is no god 无神论
〔蒋〕[a-无，theism] 无神论