Isolate the bad clues the Ed altered (7)
I believe the answer is:
seclude
'isolate' is the definition.
(secluding is a kind of isolating)
'the bad clues the ed altered' is the wordplay.
'the bad' indicates anagramming the letters.
'altered' is an anagram indicator.
'clues' anagrammed gives 'seclu'.
'ed' with letters rearranged gives 'de'.
'seclu'+'de'='SECLUDE'
(Other definitions for seclude that I've seen before include "Keep (someone) away from other people" , "Shut off" .)