Outstanding rift Eric mended (8)
I believe the answer is:
terrific
'outstanding' is the definition.
(thesaurus)
'rift eric mended' is the wordplay.
'mended' indicates an anagram.
'rift'+'eric'='rifteric'
'rifteric' anagrammed gives 'TERRIFIC'.
(Other definitions for terrific that I've seen before include "Awesome" , "Excellent; causing fear" , "frightening" , "Of great size/intensity" , "Marvellous, tremendous" .)