alien vs irregular

alien

noun
  • One excluded from certain privileges; one alienated or estranged. 

  • Any life form of extraterrestrial or extradimensional origin. 

  • A foreigner residing in a country. 

  • A person, animal, plant, or other thing which is from outside the family, group, organization, or territory under consideration. 

adj
  • Not belonging to the same country, land, or government, or to the citizens or subjects thereof; foreign. 

  • Very unfamiliar, strange, or removed. 

  • Pertaining to extraterrestrial life; typical of an extraterrestrial creature. 

verb
  • To estrange; to alienate. 

  • To transfer the ownership of something. 

irregular

noun
  • One who does not regularly attend a venue. 

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

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 

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