A reprisal is a limited and deliberate violation of international law to punish another sovereign state that has already broken them. Since the 1977 Additional Protocol I to the Geneva Conventions (AP 1), reprisals in the laws of war are extremely limited, as they commonly breach the rights of non-combatants.
The word came from French, where it originally meant "act of taking back", for example, raiding back the equivalent of cattle lost to an enemy raid.
Reprisals refer to... meer