Long-lasting bad rule replaced (7)
I believe the answer is:
durable
'long-lasting' is the definition.
(I know that long-lasting can be written as durable)
'bad rule replaced' is the wordplay.
'replaced' indicates an anagram.
'bad'+'rule'='badrule'
'badrule' is an anagram of 'DURABLE'.
(Other definitions for durable that I've seen before include "Made to last" , "Long-lasting and hard-wearing" , "existing for a long time" , "Tough and long-wearing" , "Good" .)