dragger vs two-wheel tractor

dragger

noun
  • A trawler. 

  • A vehicle used in drag racing. 

  • A car thief. 

  • Something that drags. 

  • One who takes part in drag racing. 

two-wheel tractor

noun
  • A tractor with one axle, self-powered and self-propelled, which can pull and power various farm implements such as a trailer, cultivator or harrow, a plough, or various seeders and harvesters. 

How often have the words dragger and two-wheel tractor occurred in a corpus of books? (source: Google Ngram Viewer )