age denial

Age denial is the refusal to accept or acknowledge one's true age, typically manifesting as lying about how old one is or rejecting the physical and social realities of aging.

The term applies both to individuals who misrepresent their age and to a broader cultural reluctance to confront aging: Her age denial was obvious when she claimed to be thirty-nine for the fifth year running.

The phrase can also describe systematic institutional failures to recognize age-related issues.