Definition of Yom Kippur War in US English:

proper noun

• The Israeli name for the Arab–Israeli conflict in 1973.

  Arab name October War

The war lasted for less than three weeks; it started on the festival of Yom Kippur (in that year, October 6) when Egypt and Syria simultaneously attacked Israeli forces from the south and north, respectively. The Syrians were repulsed, and the Egyptians were surrounded. A ceasefire followed, and disengagement agreements over the Suez area were signed in 1974 and 1975