doodad vs rigamajig

doodad

noun
  • Used to refer to something whose name one cannot recall: an unspecified device, gadget, part, or thing. 

rigamajig

noun
  • A thingy; a miscellaneous or nameless object. 

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