crescent spanner vs roadblock

crescent spanner

noun
  • An adjustable hand tool for tightening and loosening nuts and bolts. 

roadblock

noun
  • Something that blocks or obstructs a road. 

  • An obstacle or impediment. 

verb
  • To prevent, hinder. 

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