irregular vs libertine

irregular

adj
  • nonstandard; not conforming to rules or expectations 

  • without symmetry, regularity, or uniformity 

  • rough 

  • not regular; having sides that are not equal or angles that are not equal 

  • whose faces are not all regular polygons (or are not equally inclined to each other) 

  • not following the regular or expected patterns of inflection in a given language 

noun
  • A soldier who is not a member of an official military force and who may not use regular army tactics. 

  • One who does not regularly attend a venue. 

libertine

adj
  • Dissolute, licentious, profligate; loose in morals. 

noun
  • One who is freethinking in religious matters. 

  • Someone (especially a man) who takes no notice of moral laws, especially those involving sexual propriety; someone loose in morals; a pleasure-seeker. 

  • Someone freed from slavery in Ancient Rome; a freedman. 

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