כָּעַס (b. h.) [to be dark, hot, cmp. חמץ,] 1) to be angry, displeased. Ber. 61ᵇ top, v. כָּבֵד III. Tem. 16ᵃ (play on עַכְסָה) כל … כּוֹעֵס על וכ׳ whoever saw her became displeased with his own wife. Ned. 22ᵃ, a. fr. כל הכועס whoever allows himself to be carried away by his wrath. Ex. R. s. 45 מטרונה שכָּעֲסָה על וכ׳ a matron (queen) that was angry with the king’s daughter; a. fr.—Part. pass. כָּעוּס, f. כְּעוּסָה; pl. כְּעוּסִים, כְּעוּסוֹת. Ib. כשיהיו פניך כ׳ וכ׳ when thou shalt be angry, I shall conciliate thee &c.; (Tanḥ. Ki Thissa 27 כשאהיה אני בכעס); a. e.—V. כָּעוּס.— *2) to grow hot in the stomach, to ferment, swell. Gitt. 70ᵃ לכשתִּכְעוֹס תעמוד על מליאה Ar. (ed. מילואך) when it (the food) swells, it will just fill the capacity of thy stomach.
    Hif. - הִכְעִיס to provoke to anger. Deut. R. s. 3. שהם עתידים להַכְעִיס אותי that they are going to provoke me (through idolatry). Ab. V, 2 היו מַכְעִיסִין וכ׳ were constantly provoking (the Lord). Snh. 27ᵃ, a. fr. להַכְעִיס in a spirit of defiance, v. מוּמָר; a. fr.—Imper. אַכְעִיס (for הכעיס). Ruth R. end (ref. to Ps. IV, 5) ארגיז יצרך … א׳ יצרך ולא תחטא let thy tempter rage, but sin not; but the Rabbis say, arouse thy (good) inclination to indignation, and thou shalt not sin. [Midr. Till. to Ps. l. c. אַכְחֵישׁ … ואל יחטיאך weaken thy tempter (by ascetics) &c.; Yalk. Ps. 627;—Pesik. Shubah, p. 158ᵃ אכופס, corr. acc.]