The literal translation is: "to the ages of the ages".
The same term applied to God differs in meaning when applied to others because of the situation and the nature of those involved. When applied to those in hell, it could mean an eternity, if those there refuse to repent and accept correction, based on using their free will. "Age-abiding correction", as is applied to those in hell, is intended by God to be a duration of limited time, for the purpose of correction and restoration. That is the will of God; those there can follow His will by repenting and being liberated from hell, or rebel and stay there as long as they continue to rebel. That's why Jesus went and "preached to the spirits in prison" after His death.
That is actually not the literal translation. That is like dividing up any other phrase and saying the meaning of the phrase is the sum of each of its parts. That is not how language works.
If God wanted to tell us something was truly eternal, what word do you say he would have used?