Γηρυόνης
From LSJ
αὐτῇ καθ' αὑτὴν εἰλικρινεῖ τῇ διανοίᾳ χρώμενος → by using his mind alone by itself and uncorrupted
English (LSJ)
ου, ὁ, (γηρύω) the three-bodied Giant Geryon, Pi.I.1.13, etc.: Γηρῠονεύς, έως, Ep. ῆος, Hes.Th.287: Γηρῠών, όνος, A. Ag.870:—hence Γηρῠονίς or γηροτροφ-ηΐς, ίδος, ἡ,
A a poem on Geryon by Stesichorus, Ath.11.499e, Paus.8.3.2.