Hisstamine his-Ssssssssssss-ti-mean noun 1. A compound existent on cat fur that causes allergic reactions in many. 2. An allergen of any kind that one counters by rubbing oneself all over with cats. This is known as administering an antihisstamine. "Excessive exposure to hisstamines may cause un-fur-gettable throat closure due to swelling." -Furbelly, Paw Paw. "The Mews about Hisstamine".