Merriam-Webster Logo
SINCE 1828
Menu
dictionary thesaurus

omicron

noun
om·​i·​cron | \ ˈä-mə-ˌkrän How to pronounce omicron (audio) , ˈō-, British ō-ˈmī-(ˌ)krän How to pronounce omicron (audio) \

Definition of omicron

: the 15th letter of the Greek alphabet — see Alphabet Table

First Known Use of omicron

15th century, in the meaning defined above

History and Etymology for omicron

Middle English, from Greek o mikron, literally, small o

Keep scrolling for more

Learn More about omicron

Dictionary Entries near omicron

omer

omertà

OMG

omicron

Omicron Ceti

ominate

omination

Statistics for omicron

Look-up Popularity

Time Traveler for omicron

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

See more words from the same century

More from Merriam-Webster on omicron

Rhyming Dictionary: Words that rhyme with omicron

Comments on omicron

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

Show Comments  Hide Comments 

WORD OF THE DAY

contraption

Listen to the pronounciation of contraption

a device or gadget

Get Word of the Day daily email!

Test Your Vocabulary

Words for Summer: A Quiz

  • a closeup of a sunflower
  • Which of the following words means “of or relating to summer”?
True or False

Test your knowledge - and maybe learn something along the way.

TAKE THE QUIZ
SCRABBLE® Sprint

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

TAKE THE QUIZ
Love words? Need even more definitions?

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

Words at Play
Ask the Editors
Word Games