to grow old; to age (to become older, physically or mentally)
親は年を取ってから急に老いるように見えた。
My parent suddenly seemed to grow old after getting on in years.
人は誰でもいつかは老いるものだと考える。
I believe everyone will grow old someday.
彼は体は丈夫だが、顔に少しずつ老いる兆しが出てきた。
His body is healthy, but signs of aging have begun to show on his face.
社会も放置すれば老いる危険があると言われている。
It's said that society can age if neglected.