[om-i-kron, oh-mi-]

Origin of omicron

< Greek ō mikrón, literally, small o. Cf. omega Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for omicron

Historical Examples of omicron

  • Mira, (Omicron Ceti,) in the neck of the Whale, is a variable star.

    Letters on Astronomy

    Denison Olmsted

  • Newton presented him with one of his publications, entitled "Omicron."

  • At all events, it was not possible for him to think of anything bad when he called “Omicron.”

  • Omicron must show her face in the stars from time to time to remind the child of his love.

  • And then, on the following morning, Sir Omicron also went his way.

    Doctor Thorne

    Anthony Trollope

British Dictionary definitions for omicron


  1. the 15th letter in the Greek alphabet (Ο, ο), a short vowel, transliterated as o

Word Origin for omicron

from Greek ō mikron small o; see micro-, omega
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for omicron

15th letter of the Greek alphabet, literally "small 'o,' " from Greek (s)mikros "small," from PIE *smik-. Because the vowel was "short" in ancient Greek. Cf. Omega.

Online Etymology Dictionary, © 2010 Douglas Harper

omicron in Medicine


[ŏmĭ-krŏn′, ōmĭ-]
  1. The 15th letter of the Greek alphabet.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.