add vs decrease

add

verb
  • To combine elements of (something) into one quantity. 

  • To append (e.g. a statement); to say further information; to add on. 

  • To summon minions or reinforcements. 

  • To give by way of increased possession (to someone); to bestow (on). 

  • To make an addition; to augment; to increase; to add on. 

  • To join or unite (e.g. one thing to another, or as several particulars) so as to increase the number, augment the quantity, or enlarge the magnitude, or so as to form into one aggregate. 

  • To sum up; to put together mentally; to add up. 

  • To perform the arithmetical operation of addition. 

noun
  • The addition of a song to a station's playlist. 

  • An act or instance of adding. 

  • An additional enemy that joins a fight after the primary target. 

decrease

verb
  • To make (a quantity) smaller. 

  • Of a quantity, to become smaller. 

noun
  • A reduction in the number of stitches, usually accomplished by suspending the stitch to be decreased from another existing stitch or by knitting it together with another stitch. See Decrease (knitting). 

  • An amount by which a quantity is decreased. 

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