cop vs sergeant

cop

noun
  • A police officer or prison guard. 

  • The ball of thread wound on to the spindle in a spinning machine. 

  • A roughly dome-shaped piece of armor, especially one covering the shoulder, the elbow, or the knee. 

  • A tube or quill upon which silk is wound. 

  • A merlon. 

verb
  • To steal. 

  • To adopt. 

  • To obtain, to purchase (as in drugs), to get hold of, to take. 

  • To admit, especially to a crime or wrongdoing. 

  • To earn by bad behavior. 

  • Of a pimp: to recruit a prostitute into the stable. 

  • To (be forced to) take; to receive; to shoulder; to bear, especially blame or punishment for a particular instance of wrongdoing. 

  • To see and record a railway locomotive for the first time. 

sergeant

noun
  • A bailiff. 

  • A fish, the cobia. 

  • A title sometimes given to the servants of the sovereign. 

  • The highest rank of noncommissioned officer in some non-naval military forces and police. 

  • UK army rank with NATO code OR-6, senior to corporal and junior to warrant officer ranks. 

  • Any of various nymphalid butterflies of the genus Athyma; distinguished from the false sergeants. 

  • A lawyer of the highest rank, equivalent to the doctor of civil law. 

  • A servant in monastic offices. 

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