Extent of anger varies (5)
I believe the answer is:
range
'extent' is the definition.
(I know that range is a type of extent)
'anger varies' is the wordplay.
'varies' indicates anagramming the letters.
'anger' anagrammed gives 'RANGE'.
'of' is the link.
(Other definitions for range that I've seen before include "Area for shooting practice" , "where cattle may graze" , "Scope - cowboys' home" , "Limits - scope" , "Kitchen gadget" .)