Yom Kippur Definition

yôm kĭpər, yōm, yŏm, yôm kē-po͝or

noun

One of the Jewish High Holidays, the Day of Atonement, a fast day of repentance during which the prayers recited include the Kol Nidre, observed on the 10th day of Tishri: Lev. 16:29-34

Webster's New World

Synonyms:

Synonyms:
day-of-atonement

pronoun

A particular Jewish holiday, the day of atonement, falling on the tenth day of the Hebrew month of Tishrei.

Wiktionary

Origin of Yom Kippur

Hebrew yôm kippûr yôm day ywm in Semitic roots kippûr atonement (from kippēr to cover, atone kpr¹ in Semitic roots)

From American Heritage Dictionary of the English Language, 5th Edition
From Hebrew יוֹם כִּפּוּר (yom kippúr, “Yom Kippur", literally “day of atonement").

From Wiktionary