Poor, cutting short stag party (4,2)
I believe the answer is:
hard up
'poor' is the definition.
(similar in meaning)
'cutting short stag party' is the wordplay.
'cutting short' means to remove the last letter.
'stag' becomes 'hart' (both can mean a male deer).
'party' becomes 'dup' (Democratic Unionist Party).
'hart' with its last letter taken off is 'har'.
'har'+'dup'='HARD-UP'
(Other definitions for hard up that I've seen before include "Out of funds - it's tough" , "Struggling with budget" , "Informally short of money - that's tough" , "boracic" , "Poor" .)