sign up vs squad

sign up

verb
  • To add one's own name to the list of people who are participating in something (including amateur, but not professional, teams) 

  • To agree to purchase some good or service. 

  • To add a name to the list of people who are participating in something. 

squad

verb
  • To act as part of, or on behalf of, a squad. 

noun
  • Sloppy mud. 

  • One's friend group, taken collectively; one's peeps. 

  • A unit of tactical military personnel, or of police officers, usually of about ten members. 

  • A group of potential players from whom a starting team and substitutes are chosen. 

  • A collective noun for a group of squid. 

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