Antique precious metal’s not good (3)
I believe the answer is:
old
'antique' is the definition.
('old' can be similar in meaning to 'antique')
'precious metal's not good' is the wordplay.
'precious metal' becomes 'gold' (gold is a kind of precious metal).
'not' suggests deleting specific letters.
'good' becomes 'g' (abbreviation).
'gold' with 'g' taken away is 'OLD'.
(Other definitions for old that I've seen before include "Former; aged" , "Ancient" , "No longer young" , "Former, previous" , "SECOND PART OF 14" .)