buckle down vs freelance

buckle down

verb
  • To put forth the needed effort; to focus; become serious; apply oneself (e.g. to work or study). 

freelance

verb
  • To work as a freelance. 

  • To produce or sell services as a freelance. 

noun
  • A medieval mercenary. 

  • Someone who sells their services to clients without a long-term employment contract. 

adj
  • Of, or relating to a freelance; without employment contract. 

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