Scouse, for one in Devon area, extremely troublesome (4)
I believe the answer is:
stew
'scouse for one' is the definition.
(I know that Scouse is a type of stew)
'in devon area extremely troublesome' is the wordplay.
'in' indicates putting letters inside.
'devon area' becomes 'SW' (south west of England).
'extremely' suggests removing the centre (only the extremes of the word are used).
'troublesome' with its centre removed is 'te'.
'sw' going around 'te' is 'STEW'.
(Other definitions for stew that I've seen before include "State of anxiety; dish" , "Casserole" , "Slow cooked meat dish" , "Ragout or burgoo" , "overheated condition" .)