ep·​si·​lon | \ ˈep-sə-ˌlän How to pronounce epsilon (audio) , -lən \

Definition of epsilon

1 : the 5th letter of the Greek alphabet — see Alphabet Table
2 : an arbitrarily small positive quantity in mathematical analysis

Keep scrolling for more

Other Words from epsilon

epsilonic \ ˌep-​sə-​ˈlä-​nik How to pronounce epsilon (audio) \ adjective

Examples of epsilon in a Sentence

Recent Examples on the Web Based on the Greek letter epsilon, the euro symbol represents the coming together of nations. Patrick Di Justo, WIRED, "Europe on €10 a Day," 1 Jan. 2002

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

First Known Use of epsilon

15th century, in the meaning defined at sense 1

History and Etymology for epsilon

Greek e psilon, literally, simple e

Keep scrolling for more

Learn More about epsilon

Time Traveler for epsilon

Time Traveler

The first known use of epsilon was in the 15th century

See more words from the same century

Statistics for epsilon

Cite this Entry

“Epsilon.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/epsilon. Accessed 27 Feb. 2021.

Style: MLA
MLA Chicago APA Merriam-Webster

More from Merriam-Webster on epsilon

Britannica.com: Encyclopedia article about epsilon

Comments on epsilon

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


Test Your Vocabulary

February 2021 Words of the Day Quiz

  • squirrel in winter
  • Which is a synonym of perdure?
Name That Thing

Test your visual vocabulary with our 10-question challenge!

Universal Daily Crossword

A daily challenge for crossword fanatics.

Love words? Need even more definitions?

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