interplay vs regimen

interplay

noun
  • Interaction; reciprocal relationship. 

verb
  • To interact. 

regimen

noun
  • A syntactical relation between words, as when one depends on another and is regulated by it in respect to case or mood; government. 

  • Orderly government; system of order; administration. 

  • Any regulation or remedy which is intended to produce beneficial effects by gradual operation. 

  • object 

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