ἄρτιον

From LSJ

οἵτινες πόλιν μίαν λαβόντες εὐρυπρωκτότεροι πολύ τῆς πόλεος ἀπεχώρησαν ἧς εἷλον τότεafter taking a single city they returned home, with arses much wider than the city they captured

Source

Russian (Dvoretsky)

ἄρτιον: τό четное число (τὸ ἄ. καὶ τὸ περιττόν Arst., Plut.).