ironic vs sardonic

ironic

adj
  • Done in an insincere and mocking manner; satirical. 

  • Acting in a unserious and teasing manner. 

  • Odd or coincidental; strange. 

  • Characterized by or constituting (any kind of) irony. 

sardonic

adj
  • Disdainfully or ironically humorous. 

  • Scornfully mocking or cynical. 

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