See also: legal versus illegal, get in line, and morality of violating restrictive immigration laws.

There is very little consensus on the correct term to use for people who enter a country without authorization from the government of the country, or who overstay their visas. The typical term used, particularly in the case of people who intend to stay in the country for the long term, is “illegal immigrant.” However, there is considerable variation.

• Terms used by restrictionists: illegal (as a noun), alien (as a noun), illegal alien
• Terms used by many pro-immigrant groups and immigrant rights advocates: undocumented immigrant, undocumented worker, unauthorized immigrant.

Criticisms of use of the word “illegal”

There are many directions of criticism:

• Some criticisms focus on the legitimacy of the concept of “illegal” itself. They may draw a distinction between law and morality, or between legislation and law. For more on this, see legal versus illegal and morality of violating restrictive immigration laws.
• Another criticism is that the term “illegal” applies to actions, not persons. The act of crossing a border without authorization or of overstaying a visa may be illegal but the person does not become illegal. The use of illegal as an adjective or noun describing a person is thus considered dehumanizing. See, for instance, this article on Diversity Inc. and the “Drop the I word” public education campaign intended to stop people from using the term “illegal” to describe illegal immigrants.
• Yet another criticism is that while immigration does violate the law, this is a civil law violation rather than a criminal offense (technically, it is a matter of administrative law, not civil law, but it is on par with civil law). In this respect, it is like copyright infringement. Thus, the use of the term “illegal” is inaccurate. See, for instance, Do you think the common American perception is that illegal immigration is a crime?, a Quora question.

Criticisms of use of the word “alien”

The term alien may be construed as indicating too much of a distance or difference between the nature of natives and immigrants, considering that this term is often used for extraterrestrial species. It might also be a way of invoking the much-overrated alien invasion metaphor.

Defenses of the term “illegal”

• Memo from the Associated Press defending their use of the term.
• Language in the Immigration Debate, an article on the Center for Immigration Studies website that lauds the Associated Press for sticking to the word “illegal” but critical of them for disavowing use of “alien.”

Criticisms of use of “undocumented” instead of “illegal”

• Thomas Sowell approvingly quotes a reader who draws an analogy between nomenclature choices for illegal immigrants and drug dealers:
  

  A reader sent the following message, quoting his nephew: “Calling an illegal alien an ‘undocumented worker’ is like calling a drug dealer an ‘unlicensed pharmacist.'”

• Elsewhere, Thomas Sowell writes:
  

  We can’t even call illegal immigrants “illegal immigrants.” The politically correct evasion is “undocumented workers.” Do American citizens go around carrying documents with them when they work or apply for work? Most Americans are undocumented workers but they are not illegal immigrants. There is a difference.

• Michelle Malkin notes, in a syndicated column, notes that undocumented workers have plenty of documents. She links to a blog post by Fulford that pokes fun at the “undocumented” nomenclature.

General discussion and debate

• From “Wetbacks” to “Illegals” to “Undocumented” to … ?, a podcast on the website of Slate (November 13, 2012).
• Should we call them undocumented immigrants? by John Lee for the Open Borders blog (January 4, 2013).