overaged vs over-the-hill

overaged and over-the-hill both are adjectives.

Word	Noun	Adjective	Verb	Adverb
overaged	No	Yes	No	No
over-the-hill	No	Yes	No	No

As adjectives, overaged and over-the-hill are synonyms defined as:

Other synonyms of overaged include overage, superannuated.

overaged (adjective)	over-the-hill (adjective)
too old to be useful	too old to be useful