Princeton's WordNet

1. foreigner, alien, noncitizen, outlander(noun)

   a person who comes from a foreign country; someone who does not owe allegiance to your country

2. stranger, alien, unknown(noun)

   anyone who does not belong in the environment in which they are found

3. extraterrestrial being, extraterrestrial, alien(adj)

   a form of life assumed to exist outside the Earth or its atmosphere

4. alien, foreign(adj)

   not contained in or deriving from the essential nature of something

   "an economic theory alien to the spirit of capitalism"; "the mysticism so foreign to the French mind and temper"; "jealousy is foreign to her nature"

5. alien, exotic(verb)

   being or from or characteristic of another place or part of the world

   "alien customs"; "exotic plants in a greenhouse"; "exotic cuisine"

6. alien, alienate(verb)

   transfer property or ownership

   "The will aliened the property to the heirs"

7. estrange, alienate, alien, disaffect(verb)

   arouse hostility or indifference in where there had formerly been love, affection, or friendliness

   "She alienated her friends when she became fanatically religious"

Kernerman English Learner's Dictionary

1. alien(noun)ˈeɪl yən, ˈeɪ li ən

   a creature from space

   an alien invasion

2. alienˈeɪl yən, ˈeɪ li ən

   a foreigner

   illegal aliens

3. alien(adjective)ˈeɪl yən, ˈeɪ li ən

   ≠ familiar

   The idea seemed alien to him.

Wiktionary

1. alien(Noun)

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

2. alien(Noun)

   A foreigner residing in a country.

3. alien(Noun)

   Any life form of extraterrestrial origin.

4. alien(Verb)

   To estrange; to alienate.

5. alien(Verb)

   To transfer the ownership of something.

6. alien(Adjective)

   Pertaining to an alien.

7. alien(Adjective)

   Very unfamiliar, strange, or removed.

Origin: alien, aliene, from alienus, from alius, from h₂élyos.

Webster Dictionary

1. Alien(adj)

   not belonging to the same country, land, or government, or to the citizens or subjects thereof; foreign; as, alien subjects, enemies, property, shores

2. Alien(adj)

   wholly different in nature; foreign; adverse; inconsistent (with); incongruous; -- followed by from or sometimes by to; as, principles alien from our religion

3. Alien(noun)

   a foreigner; one owing allegiance, or belonging, to another country; a foreign-born resident of a country in which he does not possess the privileges of a citizen. Hence, a stranger. See Alienage

4. Alien(noun)

   one excluded from certain privileges; one alienated or estranged; as, aliens from God's mercies

5. Alien(verb)

   to alienate; to estrange; to transfer, as property or ownership

• vreemdeling, buitelanderAfrikaans
• غَرِيب، أجْنَبِيArabic
• чужденецBulgarian
• estrangeiroPortuguese (BR)
• cizinecCzech
• der/die Ausländer(in); aber auch AusserirrdischeGerman
• fremmedDanish
• αλλοδαπόςGreek
• extranjeroSpanish
• välismaalaneEstonian
• غریبهFarsi
• muukalainenFinnish
• étranger/-èreFrench
• זָרHebrew
• विदेशीHindi
• stranacCroatian
• idegenHungarian
• orang asingIndonesian
• útlendingurIcelandic
• stranieroItalian
• 外国人Japanese
• 외국인Korean
• svetimšalisLithuanian
• ārzemnieksLatvian
• warga asingMalay
• buitenlanderDutch
• utlending, fremmedNorwegian
• obcy, cudzoziemiecPolish
• غریبهPersian
• بیګانه ، مهاجرPashto
• estrangeiroPortuguese
• străinRomanian
• иностранецRussian
• cudzinec, -nkaSlovak
• tujecSlovenian
• stranacSerbian
• utlänningSwedish
• คนต่างด้าวThai
• yabancı uyruklu kimseTurkish
• 外國人Chinese (Trad.)
• іноземець, чужоземецьUkrainian
• غیر ملکیUrdu
• ngoại kiềuVietnamese
• 外侨Chinese (Simp.)