So... is "cizí člověk" always used in the meaning of "stranger," even if the stranger isn't (internationally speaking) a "foreigner"? Or is there another word that just means "someone I don"t know"?
cizí člověk = 'stranger'
cizinec = 'foreigner'
Does "cizi" mean more "unknown" than "foreign" then?
a foreign body in a wound - cizí těleso v ráně
cizinec - a foreigner, a stranger, an alien (a legal or illegal alien, not extra-terrestrial)