DIY buy (3)
I believe the answer is:
kit
'diy buy' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for kit that I've seen before include "Football top, shorts, stockings and boots?" , "Set of equipment, perhaps for first-aid" , "Stuff" , "Apparatus" , "Set of articles or tools" .)