VE Day (n.)

c. 1300, "military supremacy, victory in battle or a physical contest," from Anglo-French and Old French victorie (12c.) and directly from Latin victoria "victory," from past participle stem of vincere "to overcome, conquer" (from nasalized form of PIE root *weik- (3) "to fight, conquer"). V.E. ("victory in Europe") and V.J. ("victory in Japan") days in World War II were first used Sept. 2, 1944, by James F. Byrne, then U.S. director of War Mobilization [Washington Post, Sept. 10, 1944].

also V-J Day, "Victory in Japan Day," 1944; it shares an origin with VE Day.