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