complimentary vs slurring

complimentary

adj
  • With respect to the closing of a letter, formal and professional. 

  • In the nature of a compliment. 

  • Free; provided at no charge. 

slurring

noun
  • A slur mark in music. 

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