Burpee buy (4)
I believe the answer is:
seed
'burpee buy' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for seed that I've seen before include "Pip - source - children" , "What is sown" , "Biblical children" , "Top Wimbledon player" , "one very much fancied" .)