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

During World War I and World War II, Americans on the home front made huge sacrifices to support the war effort.

From MarketWatch • Mar. 20, 2026

William Sims wrote in 1920’s “The Victory at Sea” that the point of escorting Allied shipping in World War I wasn’t to protect the ships.

From The Wall Street Journal • Mar. 17, 2026

If nothing he has done, at least so far, is likely to rival the outbreak of World War I, that’s the result of chance and circumstance more than anything else.

From Salon • Mar. 15, 2026

After World War I, Woodrow Wilson barnstormed the country to gin up support for a treaty that would have seen the U.S. join the League of Nations.

From Slate • Mar. 10, 2026

For example, the assassination of Franz Ferdinand that kicked off World War I had taken three weeks of negotiations and a lifetime of headaches, according to my mother.

From "Glitch" by Laura Martin