English translation (word)
English translation (etymon)
Etym. Gudianum, alpha, p. 141
E.L. de Stefani, Etymologicum Gudianum, fasc. 1 & 2, Leipzig: Teubner, 1:1909; 2:1920
Ἀνεψιός· παρὰ τὸ ἀνῆφθαι εἰς συγγένειαν· ἢ παρὰ τὸ ἕπω ἕψω, ὁ ἄνωθεν ἑπόμενος
Anepsios "cousin" is from the fact that he is connected (anephthai) by ties of kinship; or it comes from hepō "to follow", ‹future› hepsō, he who comes next from above
Ἀνεψιός, isolated within Greek, is inherited from PIE, related to Lat. nepos "nephew, grandson", Vedic nápāt- "nephew". PIE *h2nep-ot- (Beekes, EDG)
Persistence in Modern Greek
Ανεψιός/ανιψιός still survive in Modern Greek as 'nephew' (Triandafyllidis, Dictionary of Modern Greek).
This etymology starts from an inflected form, the future which provides the sequence [ps]. It has the same short [e] as ἀνεψιός. Ἕπομαι is never combined with ἀνά, but that was not an objection for Greek etymologists. The etymology is of the descriptive type, the cousin is the one who comes after brothers and sisters when one starts from above (ἄνωθεν), that is, from the parents' generation.