Intermediate stage completed after being put back a year (4)
I believe the answer is:
pupa
'intermediate stage' is the definition.
'pupa' can be an answer for 'stage' (I have seen 'middle stage' mean 'pupa' so perhaps 'stage' could also mean 'pupa'). I am unsure of the 'intermediate' bit.
'completed after being put back a year' is the wordplay.
'completed after being' becomes 'up' (I can't explain this - if you can you should believe this answer much more).
'put back' is a reversal indicator.
'a year' becomes 'pa' (per annum).
'up' backwards is 'pu'.
'pu'+'pa'='PUPA'
Can you help me to learn more?
(Other definitions for pupa that I've seen before include "appearance of immaturity" , "A chrysalis as of butterfly" , "Insect life stage between larva and adult" , "One is growing" , "Developing butterfly" .)