Rebuilt feature lacking a counter (6)
I believe the answer is:
refute
'counter' is the definition.
(thesaurus)
'rebuilt feature lacking a' is the wordplay.
'rebuilt' is an anagram indicator.
'lacking' suggests deleting specific letters.
'feature' with 'a' taken out is 'feture'.
'feture' is an anagram of 'REFUTE'.
(Other definitions for refute that I've seen before include "Negate" , "Rebut; deny" , "Prove that statement or accusation is wrong" , "Prove something to be wrong" , "Disprove" .)