Trace very old chopped ham (7)
I believe the answer is:
overact
'ham' is the definition.
(ham can mean to overact)
'trace very old chopped' is the wordplay.
'very' becomes 'v' (abbreviation).
'old' becomes 'o' (abbreviation).
'chopped' indicates an anagram (letters chopped or smashed up).
'trace'+'v'+'o'='tracevo'
'tracevo' with letters rearranged gives 'OVERACT'.
(Other definitions for overact that I've seen before include "Be excessive like fulsome thespian" , "Perform hammily" , "Do what ham thespian does" , "Be excessive on stage" , "Be unsubtle on stage" .)