bit part vs supernumerary

bit part

noun
  • A minor role, generally not assigned a name. 

supernumerary

noun
  • A person who works in a group, association, or public office without forming part of the regular staff (the numerary). 

  • An extra or walk-on, often non-speaking, in a film or play; a spear carrier. 

  • An animal which has not formed a pair bond and is therefore single. 

  • A married man or woman who is a secular member of Opus Dei, a Roman Catholic religious institution. 

  • Something which is beyond the prescribed or standard amount or number. 

adj
  • Of an organ or structure: additional to what is normally present. 

  • Greater in number than. 

  • Beyond what is necessary; redundant. 

  • Beyond the prescribed or standard amount or number; excess, extra. 

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