Ogre in dreadful area (6)
I believe the answer is:
region
'area' is the definition.
(I know that area can be written as region)
'ogre in dreadful' is the wordplay.
'dreadful' indicates an anagram.
'ogre'+'in'='ogrein'
'ogrein' is an anagram of 'REGION'.
(Other definitions for region that I've seen before include "Area,territory" , "Ignore (anag) - area" , "Area - district" , "Area, domain" , "Area, territory" .)