Fishy fish found on the fourth of July (5)
I believe the answer is:
shady
'fishy' is the definition.
(I know that fishy can be written as shady)
'fish found on the fourth of july' is the wordplay.
'fish' becomes 'shad' (shad is a kind of fish).
'found on' is a charade indicator (letters next to each other).
'the fourth of july' becomes 'y' (4th letter of 'july').
'shad'+'y'='SHADY'
(Other definitions for shady that I've seen before include "Fishy; unlit" , "Of doubtful legality" , "Disreputable - umbrageous" , "Of questionable morality out of the sunlight" , "Suspicious, fishy" .)