Hold back new deal by year (5)
I believe the answer is:
delay
'hold back' is the definition.
(I know that delay is a kind of hold back)
'new deal by year' is the wordplay.
'new' is an anagram indicator.
'by' means one lot of letters go next to another.
'year' becomes 'y' ().
'deal' anagrammed gives 'dela'.
'dela'+'y'='DELAY'
(Other definitions for delay that I've seen before include "Procrastinate - put off" , "hold-up of train?" , "Hold-up, time lag" , "Temporise" , "Postponement" .)