Omicron

Omicron (uppercase Ο, lowercase ο, literally "small o": Όμικρον, o mikron, micron meaning 'small' in contrast to omega) is the 15th letter of the Greek alphabet. In the system of Greek numerals it has a value of 70. It is rarely used in mathematics because it is indistinguishable from the Latin letters O, o and easily confused with the digit 0. This letter is derived from the Phoenician letter ayin . In classical Greek, omicron represented the sound in contrast to omega . In modern Greek, omicron represents the sound . Letters that arose from omicron include Roman O and Cyrillic O.