It's a term improperly used for abuse (8)
I believe the answer is:
mistreat
'abuse' is the definition.
('mistreat' can be a synonym of 'abuse')
'it's a term improperly' is the wordplay.
'improperly' is an anagram indicator (I've seen this in other clues).
'its'+'a'+'term'='itsaterm'
'itsaterm' anagrammed gives 'MISTREAT'.
'used for' is the link.
(Other definitions for mistreat that I've seen before include "Deal unfairly with" , "Abuse" , "Ill-use" , "Handle badly" , "Behave badly towards" .)