שָׁכַח (b. h.; cmp. שכך) [to sink,] to forget, discard. Ber. 32ᵇ (ref. to Is. XLIX, 14) אדם … אתה עזבתני ושְׁכַחְתָּנִי if a man marries a woman after abandoning his first wife, he remembers the doings of his first wife, but thou hast abandoned me and also forgotten me. Ib. כלום אֶשְׁכַּח עולות וכ׳ will I ever forget the burnt-offerings of rams and the first born that thou didst offer &c.? Ib. שמא תִשְׁכַּח … סיני wilt thou forget what I did at Sinai? Peah V, 7 העומר ששְׁכָחוּהוּ … ולא ש׳ וכ׳ a sheaf which the laborers overlooked in collecting, but the employer had not overlooked. Ib. VII, 1 ושְׁכָחוֹ and he forgot it (left it on the tree). Ab. III, 8 כל השׁוֹכֵחַ וכ׳, v. מִשְׁנָה. Midd. II, 5 שָׁכַחְתִּי מה וכ׳ I forgot what purpose it served; Yoma 16ᵃ; a. v. fr.—Part. pass. שָׁכוּחַ; f. שְׁכוּחָה, a) (cmp. זָכוּר) forgetting. Y. Sabb. VI, 7ᵈ והיא ש׳ and she may forget herself, v. שַׁחֲצָנִית.—b) forgotten. B. Mets. 11ᵃ ש׳ מעיקרו a sheaf forgotten at the start (overlooked in collecting); זכור ולבסוף ש׳, v. זָכַר. Ber. l. c. (ref. to Is. l. c.) היינו עזובה היינו ש׳ is not abandoned the same as forgotten? (Ms. O. עֲזִיבָה … שְׁכִיחָה …).
    Pi. - שִׁכֵּחַ 1) same. Y. Ber. V, 9ᵃ top לא במהרה הוא מְשַׁכֵּחַ will not easily forget it. Snh. 99ᵃ כל … ומְשַׁכְּחָהּ וכ׳ he who studied the Law and neglects it (fails to review it) is like a woman that gives birth and buries; a. e. —2) to cause forgetting. Ab. II, 2 שיגיעת … מְשַׁכַּחַת עון (or מַשְׁכַּחַת) the employment of the mind in both of them causes man to forget sin. Tosef. Sot. III, 12 אתם מְשַׁכְּחִין … אני אֲשַׁכֵּחַ וכ׳ you make the law of free trade forgotten among you, I will cause you to be forgotten in the world; Snh. 109ᵃ, a. e. באו ונְשַׁכֵּחַ וכ׳, v. רֶגֶל; a. fr.
    Hif. - הִשְׁכִּיחַ same. Bets. 15ᵇ להַשְׁכִּיחוֹ, v. זָכַר. Ab. l. c., v. supra; a. e.
    Nif. - נִשְׁכַּח,
    Hithpa. - הִשְׁתַּכֵּחַ, , Nithpa. נִשְׁתַּכֵּחַ to be forgotten. Tem. 14ᵇ מוטב … ואל תִּשְׁתַּכֵּחַ וכ׳ (some ed. תִּשָּׁבֵחַ) it is better that a law be uprooted (disregarded) than that the Law be forgotten in Israel. Ib. 15ᵇ שלשה … נִשְׁתַּכְּחוּ וכ׳ three thousand traditional rules were forgotten during the days of mourning for Moses. Ib. 16ᵃ אף … נִשְׁתַּכְּחָה וכ׳ also the rule concerning a sin offering whose owner died (before it was brought) was forgotten during &c. Ib. שלא יִשְׁתַּכֵּחַ … מלבי that what I have learned be not forgotten out of my mind. Pes. 54ᵇ על המת שישתכח מן הלב that the dead should be forgotten out of mind; a. fr.