Ask at the forum if you have an Ancient or Modern Greek query!

sei

Ἓν οἶδα, ὅτι οὐδὲν οἶδα –> I know only one thing, that I know nothing | all I know is that I know nothing.
Diogenes Laertius, Lives of the Philosophers, Book 2 sec. 32.

Latin > French (Gaffiot)

sei, v. si.

Latin > German (Georges)

sei, s. si.