Polish vs Polonian

Polish

adj
  • Of, from or native to Poland, or relating to the Polish language. 

noun
  • A breed of chickens with a large crest of feathers. 

  • The language spoken in Poland. 

Polonian

adj
  • Synonym of Polonial 

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