1 The Term ism in Medieval Arabic Grammatical Tradition: A Hyponym of Itself 1 Almog Kasher Bar-Ilan University ABSTRACT The term ism in the Arabic grammatical tradition is a hyponym of itself. In other words, it can refer to the entire class of words belonging to the part of speech ism, or to just a subclass of this part of speech. In the latter sense it always stands in opposition to one of three other subclasses of this part of speech, viz. ṣifa, maṣdar and ẓarf; the subclass defined by the former is more focal than the one referred to by each of the latter. This interpretation resolves a difficulty stemming from cases where ism and one of the three other terms refer to two mutually exclusive classes, although the latter always refers, in the contexts in question, to a subclass of the part of speech ism. 1 This article is based mainly on Ch. 2.1 of my Ph.D. dissertation The ẓarf in Medieval Arabic Grammatical Theory (Hebrew), which was submitted to Bar-Ilan University in November 2006. The dissertation was carried out under the supervision of Dr Shlomit Shraybom-Shivtiel (Bar-Ilan University) and Prof. Yishai Peled (Tel Aviv University).