addendum vs additive

addendum

noun
  • Something to be added; especially text added as an appendix or supplement to a document. 

  • The height by which the tooth of a gear projects beyond (outside for external, or inside for internal) the standard pitch circle or pitch line. 

  • A postscript. 

additive

noun
  • A word or phrase that adds something, such as also, even, or nor. 

  • A substance added to another substance or product to produce specific properties in the combined substance. 

adj
  • Of or pertaining to genes (or the interaction etc. of such genes) which govern the same trait and whose effects work together on the phenotype. 

  • Pertaining to chemical addition. 

  • Pertaining to addition; that can be, or has been, added. 

  • That is distributive over addition. 

  • Whose operator is identified as addition. 

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