μητράδελφος
From LSJ
ἧς ἂν ἐπ' ἐλάχιστον ἀρετῆς πέρι ἢ ψόγου ἐν τοῖς ἄρσεσι κλέος ᾖ → of whom there is least talk either for praise or blame, of whom there is least notoriety among the men either for praise or blame
English (LSJ)
[ᾰδ], Dor. ματρᾰδελφεός, Pi.P.8.35: ὁ and ἡ:—
A mother's brother or sister, uncle or aunt, BGU 1158.3, Poll.3.22.
German (Pape)
[Seite 179] ὁ, u. ἡ, Mutterbruder, Mutterschwester, Oheim, Base, Poll. 3, 22.
