1. ADJ 外国的；来自国外的
Something or someone that is foreign comes from or relates to a country that is not your own.
in Frankfurt, where a quarter of the population is foreign。
She was on her first foreign holiday without her parents.
a foreign language。
2. ADJ 外交的；外国的；对外的
In politics and journalism, foreign is used to describe people, jobs, and activities relating to countries that are not the country of the person or government concerned.
the German foreign minister。
I am the foreign correspondent in Washington of La Tribuna newspaper of Honduras.
the effects of US foreign policy in the 'free world'.
3. ADJ 异质的；外来的
A foreign object is something that has got into something else, usually by accident, and should not be there.
The patient's immune system would reject the transplanted organ as a foreign object.
4. ADJ-GRADED 陌生的；不熟悉的；非典型的
Something that is foreign to a particular person or thing is not typical of them or is unknown to them.
The very notion of price competition is foreign to many schools。
The whole thing is foreign to us.