counterspy vs op.

counterspy

noun

  • A spy working in counterintelligence. 

verb

  • To carry out counterespionage. 

op.

noun

  • A detective. 

  • Opportunity. 

  • Opus. 

  • Operation. 

  • Operative. 

  • Operator. 

  • An operator's license, usually ops 

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