Tree beside grave gets emergency treatment (5,3)
I believe the answer is:
first aid
'emergency treatment' is the definition.
(I've seen this before)
'tree beside grave' is the wordplay.
'tree' becomes 'fir' (fir tree is a kind of tree).
'beside' is a charade indicator (letters next to each other) (I've seen this in other clues).
'grave' becomes 'staid' (I've seen this before).
'fir'+'staid'='FIRST-AID'
'gets' is the link.
(Other definitions for first aid that I've seen before include "medical attention" , "Emergency procedure" , "Emergency medical treatment" , "Preliminary treatment before doctor comes" , "Instant help for the sick" .)