Entirely fashionable Wizard of Oz character (2,4)
I believe the answer is:
in toto
'entirely' is the definition.
(I've seen this before)
'fashionable wizard of oz character' is the wordplay.
'fashionable' becomes 'in' (similar in meaning).
'wizard of oz character' becomes 'toto' (I can't justify this - if you can you should give a lot more credence to this answer).
'in'+'toto'='IN TOTO'
Can you help me to learn more?
(Other definitions for in toto that I've seen before include "All told" , "Completely - entirely (Latin)" , "In entirety" , "Altogether, completely" , "As a whole (Latin)" .)