λίστρον
From LSJ
Τὸ νικᾶν αὐτὸν αὑτὸν πασῶν νικῶν πρώτη τε καὶ ἀρίστη. Τὸ δὲ ἡττᾶσθαι αὐτὸν ὑφ' ἑαυτοῦ πάντων αἴσχιστόν τε ἅμα καὶ κάκιστον. → Τo conquer yourself is the first and best victory of all, while to be conquered by yourself is of all the most shameful as well as evil
English (LSJ)
τό,
A tool for levelling or smoothing, spade, shovel, Od.22.455, Lyc. 1348, Mosch.4.101:—later also λίστρ-ος, ὁ, Sch.Nic.Th.29, EM587.43.