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English definition of “alien”

alien

adjective     /ˈeɪliən/
STRANGE strange and not familiar: The custom was totally alien to her.Strange, suspicious and unnatural
ANOTHER PLANET [always before noun] relating to creatures from another planet: an alien spacecraftStrange, suspicious and unnatural things and people
(Definition of alien adjective from the Cambridge Learner's Dictionary © Cambridge University Press)

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