ὑδραύλης
From LSJ
προγράψαντες οὖν τά τε θεωρήματα καὶ τὰ ἐπιτάγματα τὰ χρεῖαν ἔχοντα εἰς τὰς ἀποδείξιας αὐτῶν μετὰ ταῦτα γραψοῦμές τοι τὰ προκείμενα → having therefore written at the beginning the theorems and the postulates that are necessary for their proofs, we will then write out for you the propositions
English (LSJ)
ου, ὁ,
A one who plays the ὕδραυλις, POxy.93.2 (iv A. D.), Cod.Just.10.48.4; also ὕδραυλος, ὁ, SIG737.4 (Delph., i B. C.).
German (Pape)
[Seite 1173] ὁ, der die Wasserorgel, ὕδραυλις spielt, Sp.