adjective. Seeming never to grow old or to show the effects of time.

adjective. Existing forever; eternal.

Without age; without definite limits of existence.

adjective. Without old age limits of duration.

adjective. Having existed for so great a period of time that its longevity cannot be expressed.

adjective. Continuing infinitely or indefinitely.

adjective. Always appearing youthful; never seeming to age.

adjective. continuing forever or indefinitely

"The other main characters are FBI agent Brad Wolgast, death row inmate Anthony Carter and young African nun Lacey in the near future thread, while in the main part, young "watchers" - ie militiamen/women of the colony that protect it from the "virals" aka ageless and seemingly non-sentient, instinct driven, "pseudo-vampires" that populate most of North America now - Peter Jaxon, Alicia Donadio and Peter's older brother Theo."

lasting  permanent  

agelessness  

all-pervading  cadaverous  catlike  changeless  clean-shaven  

age-old  ancient  antique  auld  ceaseless