Entry 2 senses Webster, 1913 Ictus /ĭkʹtəs/ · Ic·tus · IPA /ˈɪktəs/ 01 n. The stress of voice laid upon accented syllable of a word. Cf. Arsis. 1. The stress of voice laid upon accented syllable of a word. Cf. Arsis.(Pros.) See: Arsis 2. A stroke or blow, as in a sunstroke, the sting of an insect, pulsation of an artery, etc.(Med.)