noun, often capitalized
wa·​ter·​loo | \ ˌwȯ-tər-ˈlü How to pronounce waterloo (audio) , ˌwä- \
plural waterloos

Definition of waterloo

 (Entry 1 of 2)

: a decisive or final defeat or setback a political waterloo


geographical name
Wa·​ter·​loo | \ ˌwȯ-tər-ˈlü How to pronounce Waterloo (audio) , ˌwä-; ˈwȯ-tər-ˌlü, ˈwä- \

Definition of Waterloo (Entry 2 of 2)

1 city in northeast central Iowa northwest of Cedar Rapids population 68,406
2 town in central Belgium south of Brussels population 28,898

Note: In June 1815, a battle near Waterloo resulted in the decisive defeat of French Emperor Napoléon I.

3 city in southeastern Ontario, Canada, west of Kitchener population 98,780

Keep scrolling for more

Did You Know?

The Battle of Waterloo, which occurred on June 18, 1815, has given its name to the very notion of final defeat. Why? Maybe because it ended one of the most spectacular military careers in history (Napoleon's), as well as 23 years of recurrent conflict between France and the rest of Europe. In addition, it was Napoleon's second "final defeat." He was defeated and exiled in 1814, but he escaped his confinement, returned to France, and was restored to power for three months before meeting defeat at the hands of the forces allied under the Duke of Wellington near the Belgian village of Waterloo. The word waterloo first appeared in casual use the following year, 1816.

Examples of waterloo in a Sentence

Recent Examples on the Web: Noun The waterloo arrived in 1930, with the Smoot-Hawley tariff. Jay Cost, National Review, "Congress Should Fix Itself before Reclaiming Its Power," 14 June 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'waterloo.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of waterloo


1816, in the meaning defined above

History and Etymology for waterloo


Waterloo, Belgium, scene of Napoleon's defeat in 1815

Keep scrolling for more

Learn More about waterloo

Time Traveler for waterloo

Time Traveler

The first known use of waterloo was in 1816

See more words from the same year

Listen to Our Podcast about waterloo

Statistics for waterloo

Cite this Entry

“Waterloo.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/waterloo. Accessed 10 Aug. 2020.

More from Merriam-Webster on waterloo

Rhyming Dictionary: Words that rhyme with waterloo

Britannica.com: Encyclopedia article about waterloo

Comments on waterloo

What made you want to look up waterloo? Please tell us where you read or heard it (including the quote, if possible).


Test Your Vocabulary

Original Meanings Quiz

  • rembrandt painting a young scholar and his tutor
  • Which of the following is the earliest known sense of the word awe?
Spell It

Can you spell these 10 commonly misspelled words?

Add Diction

Test Your Knowledge - and learn some interesting things along the way.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!