Obscure pawnbroker meets Arab (7)
I believe the answer is:
unclear
'obscure' is the definition.
(thesaurus)
'pawnbroker meets arab' is the wordplay.
'pawnbroker' becomes 'uncle' (old-fashioned term for a pawnbroker).
'meets' is a charade indicator (letters next to each other).
'arab' becomes 'ar' (abbreviation in Chambers).
'uncle'+'ar'='UNCLEAR'
(Other definitions for unclear that I've seen before include "Imprecise, hazy" , "in clouds?" , "Indistinct" , "Not distinct in nuclear way" , "Not easy to grasp" .)