Drunk left together with Queen is northern Scot (10)
I believe the answer is:
highlander
'northern scot' is the definition.
'drunk left together with queen' is the wordplay.
'drunk' becomes 'high' (I've seen this before).
'left' becomes 'l' (common abbreviation).
'together with' becomes 'and' (I've seen this before).
'queen' becomes 'er' (abbreviation for Elizabeth Regina).
'high'+'l'+'and'+'er'='HIGHLANDER'
'is' acts as a link.
(Other definitions for highlander that I've seen before include "Flora Macdonald, perhaps" , "Scot, possibly" , "man coming from table" , "Clansperson" , "regimental soldier" .)