כֵּיסָא, כִּיסָּא m. (כְּסַס) 1) thorn (cmp. קֵיסָא).—Pl. כֵּיסִין, כֵּיסֵי, כִּיסּ׳. Y. Sabb. VI, 8ᶜ bot. מקטוע כ׳ to cut thorns. Sabb. 77ᵇ אכל כ׳ (Ms. M. בוצי, ביני, Ar. ביסי) (the camel) eats thorns. B. Mets. 42ᵇ, sq. בכ׳ … דמי כ׳ (Ms. H. ב׳, v. Rabb. D. S. a. l. note 6) when what he gave him in trust was thorns (on which the cuscuta was hanging), and he pays him the value of thorns. —2) fodder, v. כִּיסְתָא II.