immigrant vs ryegrass

immigrant

noun
  • A plant or animal that establishes itself in an area where it previously did not exist. 

  • A non-native person who comes to a country from another country to permanently settle there. 

adj
  • Of or relating to immigrants or the act of immigrating. 

ryegrass

noun
  • A collection of plants of any of the species, as in a lawn or field. 

  • Any of several species of tufted grasses of the genus Lolium. 

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