Hear about object, all the rage (6)
I believe the answer is:
trendy
'all the rage' is the definition.
(I've seen this in another clue)
'hear about object' is the wordplay.
'hear' becomes 'try' (to hear or try a case in the legal sense).
'about' is an insertion indicator.
'object' becomes 'end' (I've seen this in other clues).
'try' placed around 'end' is 'TRENDY'.
(Other definitions for trendy that I've seen before include "Stylish" , "In fashion, of popular style" , "Voguish" , "following fashion" , "Informally in the latest fashion" .)