Ageless

Ageless is an adjective describing a person or thing whose age cannot be defined, is non-existent, or appears not to change. It can also describe something that has always existed without a precise beginning or an end.

Agelessness can be used as a synonym for immortality; more specifically it refers to eternal youth.

Agelessness can be attributed to individuals whose physical or mental characteristics appear young for their biological age.

The Castrati singers of the Renaissance aged differently from other men due to the lack of testosterone and other hormones, which may have altered their appearance and stature. Specifically, Alessandro Moreschi (1858–1922) was described as having no facial hair and a childish voice and appearance.

The illusion of agelessness seems to be a goal for many individuals, such as Hollywood celebrities, that have been known to strive for, sometimes undergoing extensive and/or risky cosmetic surgeries. Demi Moore, Naomi Campbell, Eminem, Jamie Lee Curtis, and Madonna are particularly mentioned in the media for their alleged efforts to appear 'forever young'. Television host Dick Clark was often described as "America's Oldest Teenager." Many of his viewers report difficulty in perceiving typical signs of aging since the 1960s, despite him being born in 1929. The age of Andy Milonakis is also ambiguous to many viewers since he is known to possess a hormone disorder, which allows him to perform the role of a young teenager in his shows despite being much older. Another celebrity who is commonly described as having the appearance of a teenager is the actor Eddie Redmayne, born 1982, due to his virtual lack of beard growth, causing many people to report he appears no older than 20 years of age.

...
Wikipedia