Among idiosyncrasies acknowledged in fire (4)
I believe the answer is:
sack
'fire' is the definition.
(dismiss someone from their job)
'among idiosyncrasies acknowledged in' is the wordplay.
'among' says the answer is hidden in the clue.
'SACK' is hidden within 'idiosyncrasies acknowledged in'.
(Other definitions for sack that I've seen before include "Plunder - large bag" , "Container for coal etc" , "Receptacle" , "Dismiss; plunder; wine" , "Fire - plunder and destroy" .)