Longevity

Brief Summary
"Longevity" is the term given to a character that has an extremely slowed aging process.

How to Qualify
Longevity can be applied to more than just aging, and the degree as well as effectiveness of longevity varies based on the user.

Some are able to age only a few years extra, and some can age over the course of thousands of years. Longevity also applies to those who have an extremely strong immune system--to the point where diseases can spread so slowly, it would take an unrealistic amount of time for the user to be effected by it.

Universal Difference
Longevity is commonly mistaken for Immortality Type 1, where the user is immune to aging and disease.

But unlike immortality, those who have longevity do age, and thus will weaken over time, and may even die from natural causes along the way--however long this process may take.