πραγματεύεσθαι
From LSJ
Ἓν οἶδα, ὅτι οὐδὲν οἶδα → I know only one thing, that I know nothing | all I know is that I know nothing.
Greek > English (Woodhouse Verbs Reversed)
(see also πραγματεύομαι): be busily engaged in, be busy with, be engaged in, be occupied in, employ oneself, engage in, occupy oneself