Lance has the demon drink (6)
I believe the answer is:
impale
'lance' is the definition.
(thesaurus)
'the demon drink' is the wordplay.
'the demon' becomes 'imp' (I've seen this before).
'drink' becomes 'ale' (ale is a kind of drink).
'imp'+'ale'='IMPALE'
'has' acts as a link.
(Other definitions for impale that I've seen before include "Pierce, me pail (anag.)" , "Pierce with pointed stick" , "Kill by piercing with a sharp stake" , "Skewer" , "Run through with stake" .)