Roguish, got-up in French cravat (4)
I believe the answer is:
arch
'roguish' is the definition.
(I've seen this before)
'up in french cravat' is the wordplay.
'up' shows that the letters should be reversed in order (in down clue: letters go upwards).
'in' says the answer is hidden in the clue.
'hcra' is hidden in the letters of 'french cravat'.
'hcra' reversed gives 'ARCH'.
'got' acts as a link.
(Other definitions for arch that I've seen before include "Prefix meaning chief - maybe an angel" , "This enemy is major" , "Mysterious - curve" , "architectural feature" , "Curved part of the foot" .)