legitimate vs on the level

legitimate

noun
  • A person born to a legally married couple. 

verb
  • To make legitimate, lawful, or valid; especially, to put in the position or state of a legitimate person before the law, by legal means. 

adj
  • In accordance with the law or established legal forms and requirements. 

  • Lawfully begotten, i.e., born to a legally married couple. 

  • Authentic, real, genuine. 

  • Relating to hereditary rights. 

  • Belonging or relating to the legitimate theater. 

  • Conforming to known principles, or established or accepted rules or standards; valid. 

on the level

prep
  • Synonym of on the square (“discreet reference to freemasonry”) 

  • Honest(ly), sincere(ly), straightforward(ly), fair(ly). 

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