συμφοιτητής
From LSJ
μὴ κακὸν εὖ ἔρξῃς· σπείρειν ἴσον ἔστ' ἐνὶ πόντῳ → do no good to a bad man; it is like sowing in the sea
English (LSJ)
οῦ, ὁ,
A schoolfellow, Pl.Euthd.272c, Phdr. 255a, X.HG2.4.20, Arist.EN1162a33, Gal.16.684. II fellowpilgrim to the temple of Asclepius, Aristid.Or.50(26).42 (pl.), 48(24).27, 28(49).133. (Cf. φοιτητής.)