Idiot back from Odeon where Wall Street's seen (5)
I believe the answer is:
ninny
'idiot' is the definition.
(I know that idiot can be written as ninny)
'back from odeon where wall street's seen' is the wordplay.
I cannot really see how this works, but
'from' could be 'in' (I've seen this in other clues) and 'in' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for ninny that I've seen before include "dope" , "Silly billy" , "gravely so miscalled by mechanicals" , "Fool" , "Simpleton" .)