aged

noun

Pronunciation: /ˈeɪ.dʒɪd/ / /eɪdʒd/

Old.
“I knocked on the door and an aged man opened it.”
“The hanging-bowl lampshade in marbled glass was two decades pre-war – the kind that marked out aged people.”
Having the age of.
“Aged 18, he had no idea what to do with his life.”
“John Mathews, aged about 18, stood at the bar with his hands in his pockets, alike indifferent to a verdict of acquittal or guilty.”
Having undergone the improving effects of time; matured.
“aged whiskey”
“The Lethrblaka's blood, to Eragon's astonishment, was a metallic blue-green, not unlike the verdigris that forms on aged copper.”

Old people, collectively.
“the aged”
“health insurance and retirement income for the aged”