omicron

noun2

1. •
   The 15th letter of the Classical and Modern Greek alphabets (16th in Ancient and Old Greek), used in ordering lists as in naming (astronomy) the 15th star of a constellation or (epidemiology) the 15th discovered major variant of a disease.

   • The E serves both for the Epsilon and Eta; the O, both for the Omicron and Omega, and likewise for the diphthong OΥ. — 1750
2. •
   Ellipsis of Omicron variant.

noun2

1. •
   Ellipsis of Omicron variant.
2. •
   Ellipsis of Omicron Hill: a mountain in North Slope borough, Alaska, United States.