Definition - What does Tertiary Beneficiary mean?
In life insurance, a tertiary beneficiary is the person specifically designated to receive the amount of proceeds payable in a life insurance policy upon the policyholder's death where both the primary beneficiary and the secondary beneficiary are also deceased at the time of insured's death.
Insuranceopedia explains Tertiary Beneficiary
Being tertiary does not entitle the person to a third of the proceeds. It simply puts a person in line to receive the proceeds or assets if the primary and secondary beneficiaries are not there anymore when the owner or policyholder dies. If the primary or secondary beneficiaries are still alive, the tertiary beneficiary's entitlement is not activated.