oldster(n = noun.person) golden ager, old person, senior citizen - an elderly person; Array
is a kind of adult, grownup
has particulars: ancient, antediluvian, centenarian, curmudgeon, dodderer, dodo, fogey, fogy, fossil, dotard, back-number, has-been, nonagenarian, octogenarian, old boy, graybeard, greybeard, methuselah, old man, old woman, septuagenarian, sexagenarian

   An old person. H. Kingsley. [1913 Webster]

oldster, n. an old person.

Etymology:
OLD + -STER, after youngster