The word arises from the Greek ἔσχατος eschatos meaning "last" and -logy meaning "the study of", and first appeared in English around 1844. The Oxford English Dictionary defines eschatology as "the part of theology concerned with death, judgment, and the final destiny of the soul and of humankind".

before vowels prot- , word-forming element meaning "first, source, parent, preceding, earliest form, original, basic," from Greek proto- , comb. form of protos "first," from PIE pre- , from root per- (1) "forward, through" (see per).