Definition of omicron in English:



  • 1The fifteenth letter of the Greek alphabet (Ο, ο), transliterated as ‘o’.

    • ‘Later, a letter omega (that is O-mega, ‘big O’) was created for the long value, with O, known as omicron (that is, O-micron, ‘little o’), kept for the short value.’
    • ‘Finally, in the combination iota, omicron, iota, the omicron in fr.1 is regularly placed higher in the stoichos than in fr.2.’
    • ‘Some historians favour the explanation that it is omicron, the first letter of the Greek word for nothing namely ‘ouden’.’
    • ‘Then again, there are letters in the ‘model’ alphabet, such as beta, delta and omicron, which were never used by the Etruscans because their language did not include the particular sounds for which those letters stood in Greek.’
    • ‘The space between this letter and the omicron is apparently uninscribed, presumably because of the defect in the stone.’
    • ‘Thus, behind the ‘we now know’ statement lies a nu, an uncertain omicron on one fragment, and a vertical stroke on another, nonjoining fragment.’
    • ‘Ah, yes, the round letters are quite small; yes, the omicrons and omegas seem to hover, there, in the middle of the line.’
    1. 1.1Astronomy followed by Latin genitive The fifteenth star in a constellation.
      ‘Omicron Piscium’
      • ‘The golden beam flew to the constellation Omicron, the red went to Lambda, the blue to Kappa, the black to Upsilon, the white light went to Epsilon, and the purple to Tau.’


From Greek o mikron ‘small o’.