unfit vs up to

unfit

verb
  • To make unfit; to render unsuitable, spoil, disqualify. 

adj
  • Unsuitable for a particular purpose. 

  • Not fit; not having the correct requirements. 

  • Not fit, not having a good physical demeanor. 

up to

prep
  • Until. 

  • Incumbent upon; the obligation of; the duty of. 

  • Considering all members of an equivalence class the same. 

  • Within the authority or jurisdiction of. 

  • Doing; involved in. 

  • For the option or decision of. 

  • As much as; no more than. 

  • Next to; near; towards; as far as. 

  • Ready for. 

  • Capable of. 

  • Willing to participate in. 

adj
  • maximum of. 

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