Garment occasioning wild jeers on the Fourth of July (6)
I believe the answer is:
jersey
'garment' is the definition.
(jersey is a kind of garment)
'wild jeers on the fourth of july' is the wordplay.
'wild' indicates anagramming the letters.
'on' is a charade indicator (letters next to each other).
'the fourth of july' becomes 'y' (fourth letter of the word 'July').
'jeers' anagrammed gives 'jerse'.
'jerse'+'y'='JERSEY'
'occasioning' is the link.
(Other definitions for jersey that I've seen before include "Woolly" , "Garment - cow - island" , "Garment for upper body" , "Kind of sweater" , "CI; cow" .)