Asparagus unit (5)
I believe the answer is:
spear
'asparagus unit' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for spear that I've seen before include "Portion of asparagus" , "Sharp weapon" , "Stabbing, throwing, weapon" , "Asparagus shoot" , "asparagus for example" .)