indemnity : Idioms & Phrases

(Law), an act or law passed in order to relieve persons, especially in an official station, from some penalty to which they are liable in consequence of acting illegally, or, in case of ministers, in consequence of exceeding the limits of their strict constitutional powers. These acts also sometimes provide compensation for losses or damage, either incurred in the service of the government, or resulting from some public measure.
a statute passed for the protection of those who have committed some illegal act subjecting them to penalties. Abbott.

noun a clause in an insurance policy that provides for double the face value of the policy in the case of accidental death