Scratchier cat is spoiling properties (15)
I believe the answer is:
characteristics
'properties' is the definition.
(characteristic is a kind of property)
'scratchier cat is spoiling' is the wordplay.
'spoiling' is an anagram indicator.
'scratchier'+'cat'+'is'='scratchiercatis'
'scratchiercatis' is an anagram of 'CHARACTERISTICS'.
(Other definitions for characteristics that I've seen before include "marks" , "features" , "Parts" .)