Entry 1 sense Webster, 1913 Hyssop /hĭs'-əp/ · Hys·sop · IPA /ˈhɪ.səp/ 01 n. A plant (Hyssopus officinalis). The leaves have an aromatic smell, and a warm, pungent taste. 1. A plant (Hyssopus officinalis). The leaves have an aromatic smell, and a warm, pungent taste.