World War I

American  

noun

1. the war fought mainly in Europe and the Middle East, between the Central Powers and the Allies, beginning on July 28, 1914, and ending on November 11, 1918, with the collapse of the Central Powers. WWI

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World War I British  

noun

1. Also called: First World War.   Great War.  the war (1914–18), fought mainly in Europe and the Middle East, in which the Allies (principally France, Russia, Britain, Italy after 1915, and the US after 1917) defeated the Central Powers (principally Germany, Austria-Hungary, and Turkey). The war was precipitated by the assassination of Austria's crown prince (Archduke Franz Ferdinand) at Sarajevo on June 28, 1914 and swiftly developed its major front in E France, where millions died in static trench warfare. After the October Revolution (1917) the Bolsheviks ended Russian participation in the war (Dec 15, 1917). The exhausted Central Powers agreed to an armistice on Nov 11, 1918 and quickly succumbed to internal revolution, before being forced to sign the Treaty of Versailles (June 28, 1919) and other treaties

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World War I Cultural  

1. A war fought from 1914 to 1918 between the Allies, notably Britain, France, Russia, and Italy (which entered in 1915), and the Central Powers: Germany, Austria-Hungary, Bulgaria, and the Ottoman Empire. The war was sparked by the assassination in 1914 of the heir to the throne of Austria (see Sarajevo) (see also Sarajevo). Prolonged stalemates, trench warfare, and immense casualties on both sides marked the fighting. The United States sought to remain neutral but was outraged by the sinking of the Lusitania by a German submarine in 1915 and by Germany's decision in 1916 to start unrestricted submarine warfare. In 1917, the United States entered the war on the side of the Allies and helped to tip the balance in their favor. In full retreat on its western front, Germany asked for an armistice, or truce, which was granted on November 11, 1918. By the terms of the Treaty of Versailles, signed in 1919, Germany had to make extensive concessions to the Allies and pay large penalties. The government leaders of World War I included Georges Clemenceau of France, David Lloyd George of Britain, Kaiser Wilhelm II of Germany, and Woodrow Wilson of the United States. World War I was known as the Great War, or the World War, until World War II broke out. (See map, next page.)

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Usage

What was World War I? World War I was a massive military conflict in Europe between 1914–18. Joining France and Great Britain, the U. S. fought on the Allied side against the German and Austria-Hungary empires. It's often noted for its military technology, such as tanks and mustard gas, which led to a death toll the world had never seen before, estimated at over 15 million. How is World War I pronounced?[ wurld wawr wuhn ]What are some other words related to World War I?

• WWI
• First World War
• The Great War

Discover More

German discontent over the terms of the Treaty of Versailles, and over the Weimar Republic that had accepted its provisions, led to the rise of the Nazis and Adolf Hitler, who pursued warlike policies not adequately opposed by the rest of Europe. Thus, barely twenty years after World War I was over, World War II began.

American foot soldiers in World War I were popularly called doughboys.

A huge number of books, songs, and poems have been written about World War I. (See All Quiet on the Western Front; A Farewell to Arms; and “In Flanders Fields”.)

“Over There” was among the popular songs produced in the United States during the war.

November 11, the day the fighting ended, is observed in the United States as Veterans' Day.

Example Sentences

The law was enacted after World War I and is intended to preserve the domestic shipbuilding industry by restricting shipping between U.S. ports to American-made, crewed and flagged vessels.

From The Wall Street Journal • Jul. 3, 2026

Of course, in the atomic age, wars between imperial great powers, as in World War I and World War II, are no longer truly conceivable.

From Salon • Jun. 9, 2026

By World War I, the U.S. had the world’s largest Navy, as well as the biggest economy.

From Barron's • Jun. 5, 2026

After seeing Peter Jackson’s 2018 World War I documentary “They Shall Not Grow Old,” Maras had the idea to use colorized archival footage in “Pressure.”

From Los Angeles Times • May 29, 2026

But nearly three decades earlier, World War I had also been heralded as the event that would break the back of race prejudice.

From "Hidden Figures" by Margot Lee Shetterly