Chap drinking beer, seldom “discontented” northerner (8)
I believe the answer is:
dalesman
'northerner' is the definition.
(I've seen this before)
'chap drinking beer seldom discontented' is the wordplay.
'chap' becomes 'dan' ().
'drinking' is an insertion indicator.
'beer' becomes 'ale' (I've seen this before).
'discontented' suggests removing the centre.
'seldom' with its middle removed is 'sm'.
'ale'+'sm'='alesm'
'dan' going around 'alesm' is 'DALESMAN'.
(Other definitions for dalesman that I've seen before include "one from Yorkshire" , "Northerner" , "native of Yorkshire" , "who may live in Yorkshire?" .)