syndicalism vs unionism

syndicalism

noun
  • Control of government and industry by labor unions, usually achieved through revolutionary direct action. 

unionism

noun
  • The support of advocacy of a union, especially of a trade union. 

  • Support for the continuance of the United Kingdom (especially with respect to Northern Ireland). 

  • Support for the North (the Union) during the American Civil War. 

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