Word aunt misused proves inappropriate (8)
I believe the answer is:
untoward
'inappropriate' is the definition.
(I've seen this in another clue)
'word aunt misused' is the wordplay.
'misused' is an anagram indicator.
'word'+'aunt'='wordaunt'
'wordaunt' is an anagram of 'UNTOWARD'.
'proves' acts as a link.
(Other definitions for untoward that I've seen before include "Unexpected, adverse" , "Adverse - out of the ordinary" , "Unlucky" , "vexing" , "Not in keeping with accepted standards" .)