donor vs settlor

donor

noun
  • One who makes a donation. 

  • A group or molecule that donates either a radical, electrons or a moiety in a chemical reaction. Compare acceptor. 

settlor

noun
  • A person who settles property on express trust for the benefit of beneficiaries. 

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