o vs omicron

o

• A zero (used in reading out numbers). 

• Operator 

• The name of the Latin-script letter O/o. 

• Object, see SVO 

• Over 

• The fifteenth letter of the English alphabet, called o and written in the Latin script. 

omicron

• 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.