dirty blonde vs fallow

dirty blonde

adj
  • Of a dark blonde colour/color bordering on light brown. 

noun
  • A dark shade of blonde, bordering on light brown. 

  • A person with dark blonde hair. 

fallow

adj
  • Of a pale red or yellow, light brown; dun. 

  • Ploughed but left unseeded for more than one planting season. 

  • Left unworked and uncropped for some amount of time. 

  • Inactive; undeveloped. 

verb
  • To make land fallow for agricultural purposes. 

noun
  • Uncultivated land. 

  • The ploughing or tilling of land, without sowing it for a season. 

  • Ground ploughed and harrowed but left unseeded for one year. 

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