ἀδελφιδοῦς
From LSJ
ὁ γὰρ ἀποθανὼν δεδικαίωται ἀπὸ τῆς ἁμαρτίας → anyone who has died has been set free from sin, the person who has died has been freed from sin, someone who has died has been freed from sin (Romans 6:7)
German (Pape)
[Seite 32] ὁ, Neffe, Bruder- od. Schwestersohn, 'Thuc. u. Folgde.
French (Bailly abrégé)
v. ἀδελφιδέος.
Russian (Dvoretsky)
ἀδελφιδοῦς: стяж. к ἀδελφιδεός.
Lexicon Thucydideum
filius fratris vel sororis, son of a brother or sister, 2.101.6. 4.101.5.