Northerner in boozer catching cold (4)
I believe the answer is:
scot
'northerner' is the definition.
(I've seen this before)
'boozer catching cold' is the wordplay.
'boozer' becomes 'sot' (I've seen this in other clues).
'catching' is an insertion indicator.
'cold' becomes 'c' (eg on taps).
'sot' enclosing 'c' is 'SCOT'.
'in' is the link.
(Other definitions for scot that I've seen before include "Payment" , "Aberdonian perhaps" , "Native of northern Great Britain" , "Northerner; old tax" , "Eg Aberdonian" .)