From Longman Dictionary of Contemporary Englishcollateral damagecollateral damagea) when non-military people are hurt or killed, or non-military property is damaged, as a result of actions in a war – used especially by the army, navy etc Hitting any non-military targets would risk ‘collateral damage’. b) unintended harm that happens to people as a result of something that is done → collateral
Examples from the Corpus
collateral damage• Our helplessness, outrage and fear were not collateral damage.• It could also be that collateral damage from a program crash has changed the setting.• This collateral damage to otherwise healthy bits of tooth may in the end have to be dealt with itself. 