Disregard rebuilt region (6)
I believe the answer is:
ignore
'disregard' is the definition.
(I know that disregard can be written as ignore)
'rebuilt region' is the wordplay.
'rebuilt' is an anagram indicator.
'region' anagrammed gives 'IGNORE'.
(Other definitions for ignore that I've seen before include "Cut head off" , "Region (anag)" , "bypass" , "Region in which to snub" , "Pass over" .)