refuse vs sign on

refuse

verb
  • To decline a request or demand, forbear; to withhold permission. 

  • To melt again. 

  • To decline (a request or demand). 

  • To throw back, or cause to keep back (as the centre, a wing, or a flank), out of the regular alignment when troops are about to engage the enemy. 

adj
  • Discarded, rejected. 

noun
  • Collectively, items or material that have been discarded; rubbish, garbage. 

sign on

verb
  • To begin broadcasting a radio or television signal, usually at the beginning of a broadcasting day and after being off the air for several hours. 

  • To commit oneself, as to a project, a goal, an organization, a cause. 

  • To join something, after signing. 

  • To apply to receive unemployment benefits. 

  • To log on; to start using a computer, radio, etc., or to start talking. 

noun
  • The time of day when a radio or television station begins broadcasting, usually after being off the air for several hours. 

How often have the words refuse and sign on occurred in a corpus of books? (source: Google Ngram Viewer )