Revealed by Indo-Persian fool (4)
I believe the answer is:
dope
'fool' is the definition.
(both can mean a stupid person)
'revealed by indo-persian' is the wordplay.
'revealed by' says the answer is hidden in the clue.
'DOPE' is hidden within 'indo persian'.
(Other definitions for dope that I've seen before include "Inside information (slang)" , "Informal drug or stupid person" , "Weed perhaps" , "The idiot's a drug" , "Silly ass takes drugs" .)