κεραυνοσκοπία
From LSJ
Ἔοικα γοῦν τούτου γε σμικρῷ τινι αὐτῷ τούτῳ σοφώτερος εἶναι, ὅτι ἃ μὴ οἶδα οὐδὲ οἴομαι εἰδέναι → I seem, then, in just this little thing to be wiser than this man at any rate, that what I do not know I do not think I know either
English (LSJ)
ἡ,
A divination by thunder and lightning, D.S. 5.40.
German (Pape)
[Seite 1423] ἡ, Beobachtung u. Deutung des Donners, D. Sic. 5, 40.