יוֹם m.n. (pl. יָמִים) 1 day. 2 time. 3 year. [Related to BAram., Aram., and Syr. יוֹם, יוֹמָא, Ugar. ym, Arab. yaum, Akka. ūmu (= day), Ethiop. yōm (= today), Aram. יְמָמָא, Syr. אִימָמָא (= day; in contradistinction to ‘night’). cp. יוֹמָא, יְמָמָה.] Derivatives: יוֹמוֹן, יוֹמִי, יוֹמָם, יוֹמִן, יוֹמְיוֹמִי. cp. the second element in בַּרְיוֹם.

יוֹם (b. h.) light, day (opp. night); (astronomical) day; trnsf. day of life; time. Gen. R. s. 6 הי׳ והגשמים וכ׳ the noise of the moving light (Yoma 20ᵇ קול גלגל חמה) and the rains &c.; Midr. Sam. ch. IX. Gen. R. l. c. (ref. to Mal. III, 19) י׳ שהוא מלהט וכ׳ it is the day light which will glow the wicked (cmp. נַרְתֵּק). M. Kat. 25ᵇ (ref. to Am. VIII, 9) זה יוֹמוֹ של וכ׳ that means the day of life of Josiah (who was slain in the bloom of manhood). Gen. R. s. 3 (ref. to ib. I, 5) י׳ אחד … ואיזה זה יוה"כ ‘one (distinguished) day’ … that is the Day of Atonement. Ḥull. V, 5 (83ᵃ) הי׳ הולך וכ׳ the day follows the night, i.e. the beginning of the night is the beginning of the new day. Taan. 29ᵃ, v. זַכַּאי; a. v. fr.—י׳ טוב (abbr. יו"ט) Holy Day; festival. R. Hash. IV, 1; a. fr.—Yoma VII, 4 ויו"ט היה וכ׳ and the Highpriest gave a festival to his friends; a. fr.—Yom Tob, name of a treatise of the Tosefta (v. בֵּיצָה).—י׳ הכפורים (abbr. יו"כ, יה"כ) Day of Atonement. Yoma I, 1; a. v. fr.—בֶּן יוֹמוֹ of the same day, not quite one day old, used on the same day. Sabb. 151ᵇ. B. Kam. 65ᵇ; a. fr.—Tanḥ. Kor. 3; ed. Bub. 6; Num. R. s. 18 תינוקות בְּנֵי יוֹמָן (not בן) children just born; a. fr.—Du. יוֹמַיִם. Mekh. Mishp., N’zikin, s. 7; B. Kam. 90ᵃ ישנו בדין יום או י׳ comes under the law of ‘one or two days’ (Ex. XXI, 21) ; B. Bath. 50ᵃ.—Mekh. l. c. יום שהוא כי׳ וי׳ שהוא כיום a time which counts like two days, and two days which count like a day, which is twenty four hours (from the time of the accident, including part of this and part of the next day).—Snh. 65ᵇ מה יום מיומים (Ms. M. a. Rashi מה היום וכ׳) what difference is there between to-day (Sabbath) and the next day?; Gen. R. s. 11; Yalk. Deut. 918; Yalk. Lev. 617.—Pl. יָמִים; constr. יְמֵי, יְמוֹת. Erub. III, 6 לשני י׳ for both days. Zeb. V, 7 לשני י׳ during two days and one night. Pes. 52ᵃ, a. fr. שני י׳ טובים של גליות, v. גָּלוּת. Taan. IV, 8 לא היו י׳ ט׳ וכ׳ Israel had no days as merry as &c.; a. fr.—Ab. I, 17, a. fr. כל יָמַי all my lifetime.—Esp. יְמוֹת season, period of. י׳ הגשמים, v. גֶּשֶׁם I.—י׳ החמה a) summer season. Toh. VI, 7; a. fr.—b) the solar year. Gen. R. s. 33, end; a. fr.—י׳ הלבנה the lunar year. Ib.; a. fr.—י׳ בגרות, י׳ נערות, v. בַּגְרוּת &c.