emigrant vs expat

emigrant

noun
  • Someone who leaves a country to settle in a new country. 

  • Any of various pierid butterflies of the genus Catopsilia. Also called a migrant. 

expat

noun
  • An expatriate; a person who lives outside their own country. 

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