declining years; old age
A literary, somewhat poetic term for the later years of life, often with a nuance of physical or mental decline. Rare in everyday speech; more common equivalents include 晩年 (ばんねん) or 老齢 (ろうれい).
Even in his declining years, he never lost his creative drive.
The exact derivation is uncertain; the kanji 頽 means 'decline' or 'crumble', and 齢 means 'age', so the compound literally suggests 'crumbling age'.