filch vs trouser

filch

verb
  • To illegally take possession of (something, especially items of low value); to pilfer, to steal. 

noun
  • Something which has been filched or stolen. 

  • An act of filching; larceny, theft. 

trouser

verb
  • To secretively steal (an item or money) for personal use. 

  • To put (money) into one's trouser pocket; to pocket. 

  • To take and keep (something, especially money, that is not one's own); to pocket. 

noun
  • A pair of trousers. 

  • Of or relating to trousers. 

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