1.Definition: not belonging to that in which it is contained; introduced from an outside source

"Foreign particles in milk"

Related Adjective(s):extraneous

2.Definition: not contained in or deriving from the essential nature of something

"The mysticism so foreign to the French mind and temper", "Jealousy is foreign to her nature"

Related Adjective(s):alien

3.Definition: of concern to or concerning the affairs of other nations (other than your own)

"Foreign trade", "A foreign office"

4.Definition: relating to or originating in or characteristic of another place or part of the world

"Foreign nations", "A foreign accent", "On business in a foreign city"

Related Adjective(s):strange