Relationship between adelphos and parthenios?

[dubmdell]

I know that a parthenios is a "son of an unmarried woman" and adelphos is literally "son of the same mother," so I was wondering if there's any connection between these two words, and if so, how they might relate.

[Markos]

There is no obvious connection. LSJ says of δελφὺς "derivation uncertain" and of παρθένος "derivation unknown." This doesn't stop less restrained etymologists from taking guesses (the former is linked variously to θῆλυς and ἑλεῖν, while the later is linked to, among others, παραθεῖναι, παραθέω, and ἐπάρθην) but any connection would be highly speculative and would, of course, per the etymological fallacy, be of little use in determining meaning.

[Scribo]

Ouch, some months later but I've only just saw this. No, there is no etymological relationship between the two. Adelphos for example literally means from the same womb (check the rule for what happens to historical *gwh before e). Parthenios is interesting not just etymologically but in terms of Greek social structure since the child is assigned to the unwed woman and not its putative (?) father.