A medic wearing jumper with posh torch (8)
I believe the answer is:
flambeau
'torch' is the definition.
(I know that flambeau is a type of torch)
'a medic wearing jumper with posh' is the wordplay.
'medic' becomes 'mb' (Bachelor of Medicine).
'wearing' means one lot of letters goes inside another.
'jumper' becomes 'flea' (something that jumps).
'with' says to put letters next to each other.
'posh' becomes 'u' (abbreviation for upper-class - opposite to non-U).
'a'+'mb'='amb'
'amb' put within 'flea' is 'flambea'.
'flambea'+'u'='FLAMBEAU'
(Other definitions for flambeau that I've seen before include "Old blazer" , "Torch; candlestick" , "Flaming torch" , "One may be burning" , "Burning torch" .)