Wear ostentatiously, just for fun (5)
I believe the answer is:
sport
This clue could be a double definition.
'wear ostentatiously just for' is the first definition.
'sport' can be an answer for 'wear' (I've seen this before). I am unsure of the 'ostentatiously just for' bit.
'fun' is the second definition.
(synonyms)
Can you help me to learn more?
(Other definitions for sport that I've seen before include "Game; display" , "entertainment" , "Fun; wear" , "Exhibit publicly; eg soccer" , "Games" .)