διορύσσειν
From LSJ
ὁ γὰρ μανθάνων κιθαρίζειν κιθαρίζων μανθάνει κιθαρίζειν → he who is learning the harp, learns the harp by harping
Greek > English (Woodhouse Verbs Reversed)
(see also διορύσσω): dig, undermine, burrow through, dig through
Lexicon Thucydideum
perfodere, to pierce through, perforate, 2.3.3.