Expand the use of detail (6)
I believe the answer is:
dilate
'expand' is the definition.
(thesaurus)
'the use of detail' is the wordplay.
'the use of' indicates an anagram.
'detail' with letters rearranged gives 'DILATE'.
(Other definitions for dilate that I've seen before include "Widen like eye pupils" , "Widen as eye pupils may" , "Enlarge or widen, like pupils perhaps" , "Become wider or more open" , "Expand in detail" .)