• synonyms


[ om-i-kron, oh-mi- ]
/ ˈɒm ɪˌkrɒn, ˈoʊ mɪ- /


the 15th letter of the Greek alphabet (O, o).
the vowel sound represented by this letter.

Nearby words

omer, omerta, omertà, omg, omi, omicron, omigod, ominous, ominously, omissible, omission

Origin of omicron

< Greek ō mikrón, literally, small o. Cf. omega Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for omicron

British Dictionary definitions for omicron


/ (əʊˈmaɪkrɒn, ˈɒmɪkrɒn) /


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

Medicine definitions for omicron


[ ŏmĭ-krŏn′, ōmĭ- ]


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.