| A | B |
| Arms Race | a contest to build weapons and military power |
| Terrorist | A person who uses violence for political cause |
| Stalemate | A situation in which neither side wins nor loses |
| Militarism | the idea of increasing military size and strength of weapons |
| Alliances | Friendly and/or trusting of another nation |
| Imperialism | the idea of increasing colonies and trading partners |
| Nationalism | the idea of believing one's own nation is better than others |
| Central Powers | Germany, The Ottoman Empire and Austria Hungary |
| Allied Nations | Great Britain, US and Russia |
| Lusitania | Ship carrying weapons that was destroyed by a German U-boat |
| Franz Ferdinand | Future leader of Austria-Hungary that was assassinated to ignite World War I. |
| U-boat | New type of submarine used by the Germans |
| Woodrow Wilson | U.S. President during World War I |
| Zimmerman Telegram | A note stating that Germany would help Mexico gain lost territories back from the U.S. if Mexico agreed join the Central Powers. |
| Propaganda | The spreading of ideas, information, and beliefs to help or hurt a cause |
| Ambassador | A person sent to another country to speak for the government of his or her own country |
| Neutral Nations | Spain, Switzerland, Denmark, Norway, Sweden |
| Victory Garden | a garden in which citizens raised their own food during World War I |
| Bond | A paper that shows debt, or money owed |
| Communism | An economic system in which the government owns all property and businesses |
| Armistice | An agreement to stop fighting |
| Meatless Tuesday | A day when supporters of the war effort in U.S. did not eat meat. |
| Wheat-less Wednesday | A day when supporters of the war effort in U.S. did not eat wheat. |
| Selective Service Act | Draft law started in the United States to increase military numbers |