ictus

History and Etymology for ictus

borrowed from Latin, "stroke, blow, beat (in music or metrics)," from ic-, variant stem of īcere "to strike with a weapon, smite, affect strongly" (perhaps going back to Indo-European *h₂i-h₂iḱ-é-, reduplicated present stem from a verbal base *h₂ei̯ḱ- "to run through (with something pointed), spear") + -tus, suffix of action nouns

Note: For nominal derivatives of *h₂ei̯ḱ- see etymology at aichmophobia. If such a verbal base exists, the only evidence for its survival in a verb would be Latin īcere (assuming the correctness of the etymology).