Onion relative (7)
I believe the answer is:
shallot
'onion relative' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for shallot that I've seen before include "found in the allotment" , "salad vegetable" , "Small onion" , "Small onion-like bulb used for seasoning" , "Onion-like plant with clusters of bulbs" .)