irregular vs trooper

irregular

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. 

adj
  • 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) 

  • nonstandard; not conforming to rules or expectations 

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

trooper

noun
  • A soldier of private rank in cavalry or armour. 

  • One who endures adversity or hardship with an attitude of stoicism and persistence. 

  • A cavalry horse; a charger. 

  • A mounted policeman. 

  • A soldier. 

  • A troopship. 

verb
  • To work steadily at an unpleasant job without complaint. 

  • To work as a trooper. 

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