check off vs signify

check off

verb
  • To mark items on a list (with a checkmark or by crossing them out) that have been chosen for keeping or removal or that have been dealt with (for example, completed or verified as correct or satisfactory); to tick off (UK), tick (UK), cross off, strike off. 

  • To carry out a decision recorded through the process of checking off an item on a list, including dealing with it, removing it from the possible choices, or removing the not checked items from further consideration. 

  • To deduct union members' dues from their wages. 

signify

verb
  • To create a sign out of something. 

  • To show one’s intentions with a sign etc.; to indicate, announce. 

  • To mean; to betoken. 

  • To make a difference; to matter (in negative or interrogative expressions). 

  • To give (something) a meaning or an importance. 

How often have the words check off and signify occurred in a corpus of books? (source: Google Ngram Viewer )