Klein Dictionary, כסכס ᴵᴵ

כסכס ᴵᴵ to rub.
    — Pilp. - כִּסֽכֵּס he rubbed, scrubbed.
    — Pulp. - כֻּסְכַּס was rubbed. [Of uncertain origin. Perhaps a special development of כסכס ᴵ.] Derivatives: כִּסְכּוּס ᴵᴵ, כַּסְכֶּסֶת.