The noun ανεψιος (anepsios) means cousin, and comes with a feminine counterpart ανεψια (anepsia). These words are surprisingly rare in the classics, also because any level of intimate familiarity would quickly result in the declaration of brotherhood. There is some indication that our word ανεψιος (anepsios) relates to αδελφος (adelphos), brother, the way "distant acquaintance" relates to "close friend": Hence Hector cries out to Melanippus: "Does your dear heart feel nothing for you slain cousin?" (Il.5.554, also see Iliad 9.464, where our noun occurs in tandem with "fellows").

Our word derives from a widely attested Proto-Indo-European noun "nepots", meaning grandson or distant descendant, which only in the western end of the language basin became synonymous with cousin. In Latin, this noun morphed into nepos, also meaning grandson or distant descendant but also cousin or nephew. In English, we have the words "nephew" and "nepotism" from this same source.

Our noun ανεψιος (anepsios) occurs in the New Testament in Colossians 4:10 only.