כִּסְכֵּס (v. כְּסַס) 1) to rub, scour. Nidd. IX, 7 וצריך לכַסְכֵּס וכ׳ one must scour with these substances three times. Sabb. 141ᵃ מְכַסְכְּסוֹ מבפנים he may rub the mud off from the inside. Y. ib. VII, 10ᵃ bot. ובלבד שלא יְכַסְכֵּס provided that he does not rub. —2) to chew, gnaw, v. כָּסַס.