omicron
UK[ˈɒmɪkrɒn]US[ˈɑːmɪkrɑːn]
n
The 15th letter of the Greek alphabet (Ο, ο)
Etymology
The word 'omicron' entered English in the 15th century as the name for the 15th letter of the Greek alphabet. It is a direct borrowing from the Greek 'o mikron', literally meaning 'small o' or 'little o'. This name distinguishes it from 'omega' ('o mega' or 'great o'), reflecting the difference in vowel length in ancient Greek pronunciation. In modern English, its primary use remains in referencing the Greek alphabet, though it gained widespread public recognition in the early 21st century as a naming convention for variants of the SARS-CoV-2 virus.
Analysis
This is a simplex word, a direct borrowing from Greek. It is not productively segmented into meaningful sub-parts in English.
Examples
Omicron is the fifteenth letter of the Greek alphabet.
The virus variant was designated Omicron by the World Health Organization.
In the Greek numeral system, omicron has a value of seventy.