Plot to develop rocket, for example (9)
I believe the answer is:
allotment
'plot' is the definition.
(I've seen this before)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for allotment that I've seen before include "cultivated area" , "grant?" , "Rented piece of ground" , "Vegetable plot" , "Piece of land let out for cultivation" .)