ὑδροφαντική
From LSJ
ῥεῖα δ' ἀρίζηλον μινύθει καὶ ἄδηλον ἀέξει, ῥεῖα δέ τ' ἰθύνει σκολιὸν καὶ ἀγήνορα κάρφει → easily he humbles the proud and raises the obscure, and easily he straightens the crooked and blasts the proud (Hesiod, Works and Days 6-8)
English (LSJ)
(sc. τέχνη), ἡ, the art of discovering water, Gp. 2.6.1; also ὑδροφαντικά, τά, ibid.
German (Pape)
[Seite 1174] ἡ, sc. τέχνη, die Kunst, verborgenes Wasser zu entdecken.