o vs Ο

o

character

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

noun

  • A zero (used in reading out numbers). 

  • Operator 

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

  • Object, see SVO 

adj

  • Over 

Ο

How often have the words o and Ο occurred in a corpus of books? (source: Google Ngram Viewer )