Where does “omicron” come from?

omicron (English) comes from Latin omicron, from Koine Greek ὂ μῑκρόν.

omicron (English): The 15th letter of Classical and Modern Greek,...

Definitions

Step	Language	Word	Meaning
1	Latin	omicron	—
2	Koine Greek	ὂ μῑκρόν	—

omicron — Etymology, Origin & Word History | Etymology Explorer