human shield | meaning of human shield in Longman Dictionary of Contemporary English | LDOCE

From Longman Dictionary of Contemporary Englishhuman shieldˌhuman ˈshield noun [countable]    someone who is taken and kept as a prisoner by a criminal in order to protect the criminal from being killed, injured, or caughtExamples from the Corpushuman shield• Denis says they're using the children as a human shield.• There was even some laughter when one of the thieves picked up a little girl to use as a human shield.