"Indemnity" means financial compensation for a loss. In life insurance, indemnity comes in the form of a death benefit. "Double indemnity," then, means getting two death benefits for a single death.
Life insurance policies that offer double indemnity pay out an additional death benefit if the insured person dies of accidental causes. That means that If you are killed by a falling tree, you get two death benefits; if you die from heart disease, however, you receive only a single death benefit. Examine your policy to see what consistutes an accident. Even homicide may get you a second death benefit.
The value of the second death benefit may be but is not necessarily equal to the life insurance policy's face amount.
Offering double indemnity imposes a larger risk on the life insurance company than offering only a single death benefit would do, so life insurance with double indemnity generally costs more than single-indemnity life insurance of comparable value. Notwithstanding, the cost is not so much greater than ordinary because accidental death is rare in the US.
Double indemnity exists as a rider more often than as a standard provision in a life insurance policy. A rider is a contractual provisions (or collection of provisions) that is not part of a standard contract but which can be attached to a contract. If you find a life insurance policy which doesn't provide double indemnity, you may be able to obtain double indemnity by attaching a rider to your policy. Make the request to your salesperson .