Edgar's strange rating (5)
I believe the answer is:
grade
'rating' is the definition.
(I know that grade is a type of rating)
'edgar's strange' is the wordplay.
'strange' indicates anagramming the letters.
'edgar' anagrammed gives 'GRADE'.
(Other definitions for grade that I've seen before include "Degree" , "School mark" , "Rank or status" , "Particular level of rank, quality, etc" , "one of the entertainment moguls" .)