dotage; feeble-minded old man; senile old fool; dotard
remaining years (of one's life)
study hard while you are young; (lit.) boys grow old easily but getting learned is harder
repetitious harping of the elderly; oft-repeated tales by old folks; tedious and repetitive talk of old people; old man's rambling
growing old together (as a married couple)
even an outstanding person becomes inferior when getting old