From Aramaic כִּיסָא (kīsā, “sack; purse”); from Akkadian 𒋢𒃻𒉌𒌓 (kīsum, “leather bag for weights and silver”); cognates with Classical Syriac ܟܺܝܣܳܐ (kīsā) and Hebrew כִּיס (kis).
Practice speaking and memorizing "كيس" and many other words and sentences in Arabic.