Achillean,a.|ˌækɪˈliːən|[f.Achille-sprop.name of a Grecian hero + -an.]Resembling Achilles; invulnerable, invincible.1637GillespieEng.Popish Cer. C 3We are not well advised to enter into combate with such Achillean strength.1849W. Fitzgeraldtr.Whitaker, Disputation 276How well this reason deserves to be considered Achillean, will appear hereafter.