πηδάλιον
Alt. πηδάλιον, ου, τό,
Etym. πηδός
1. "a rudder or an oar used for steering", Od.; after Homer, a Greek ship commonly had two πηδάλια joined by cross-bars (ζεῦγλαι) and worked by "a handle or tiller" (οἴαξ).
2. metaph., ἱππικὰ π. of reins, Aesch.; πηδαλίῳ δικαίῳ νωμᾶν στρατόν Pind.; τὰ π. τῆς διανοίας Plat.