Symbol of Wales (4)
I believe the answer is:
leek
'symbol of wales' is the definition.
(the leek is an emblem of Wales)
This is all the clue.
(Other definitions for leek that I've seen before include "Vegetable symbol of Wales" , "Vegetable of the onion family" , "Foodstuff" , "Bulb" , "One of the veggies" .)