"Over-the-hill" is a phrase used to describe someone who is past their prime, typically in reference to their age or performance in a certain area. There are various synonyms for this phrase, such as "past your prime," "past it," "past the zenith," "past the peak," "past your sell-by date," "past your expiration date," "past your best," "past your use-by date," "past the age of excellence," and "past the age of achievement." These synonyms all convey the idea of someone who is no longer as capable or successful as they once were, and who may be on the decline. However, they vary in their tone and connotation, from straightforward and matter-of-fact to more humorous or even insulting.