Yom Kippur

noun1

1. •
   (Judaism) A particular Jewish holiday, the day of atonement, falling on the tenth day of the Hebrew month of Tishrei.

   • Waving chickens above their heads, ultra-Orthodox Jews in Israel performed the ritual of "kaparot" ahead of Yom Kippur, the most sacred day of the Jewish calendar, which begins at sundown on Tuesday. — 2018