The term 'past one's prime' is used to describe someone who is no longer in their best physical or mental condition. The crossword solutions for this term are AGED (4 letters), OLD (3 letters), AGING (5 letters), FADED (5 letters), OVERTHEBEAN (11 letters), and OVERTHEHILL (11 letters). All of these words can be used to describe someone who is no longer in their prime, as they suggest a person who is AGING, OLD, and FADED from their former glory.