Pressure to order liners some lager (7)
I believe the answer is:
pilsner
'some lager' is the definition.
(type of lager)
'pressure to order liners' is the wordplay.
'pressure' becomes 'p' (abbreviation).
'to order' is an anagram indicator.
'liners' anagrammed gives 'ilsner'.
'p'+'ilsner'='PILSNER'
(Other definitions for pilsner that I've seen before include "drink" , "Bar tab might include this" , "Type of lager" , "Czech beer" , "alcohol" .)