over the hill
• old and past one's best.
• "a once famous ballerina, now over the hill"
Similar:
past one's prime,
not as young as one was,
not as young as one used to be,
in one's dotage,
long in the tooth,
as old as the hills,
elderly,
old,
aged,
senior,
ancient,
venerable,
decrepit,
doddering,
doddery,
not long for this world,
past it,
no spring chicken,
senescent,
