(~s)
1.
Alien means belonging to a different country, race, or group, usually one you do not like or are frightened of. (FORMAL)
He said they were opposed to the presence of ~ forces in the region.
= foreign
ADJ: usu ADJ n disapproval
2.
You use ~ to describe something that seems strange and perhaps frightening, because it is not part of your normal experience.
His work offers an insight into an ~ culture.
= unfamiliar
ADJ: usu ADJ n
3.
If something is ~ to you or to your normal feelings or behaviour, it is not the way you would normally feel or behave. (FORMAL)
Such an attitude is ~ to most businessmen.
= foreign, unfamiliar
ADJ: v-link ADJ to n
4.
An ~ is someone who is not a legal citizen of the country in which they live. (FORMAL or LEGAL)
= foreigner
N-COUNT
5.
In science fiction, an ~ is a creature from outer space.
N-COUNT