τρωτήριον
From LSJ
ὅτι τίς ὁ ἄνθρωπος, ὃς ἐπελεύσεται ὀπίσω τῆς βουλῆς τὰ ὅσα ἐποίησεν αὐτήν; (Ecclesiastes 2:12, LXX version) → for who is the man who, after following his own plan, will find wisdom (in) everything he has done?
τρωτήριον: τό, ὄργανον τρωτικόν, Καισάρ. σ. 1040, ἔκδ. Mi.