Latin word ictus comes from Latin ico (I hit, strike or smite. I stab or sting.)

Detailed word origin of ictus

Dictionary entry	Language	Definition
ico	Latin (lat)	I hit, strike or smite. I stab or sting.
ictus	Latin (lat)	(prosody, music) a beating time, a beat. A beat of the pulse. A blow, stroke, stab, thrust, bite, sting. A striking, playing on the lyre. A stroke of lightning, lightning. An attack, shot. The stroke of a wing.