Root vegetable used in salads (6)
I believe the answer is:
radish
'root vegetable used in salads' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for radish that I've seen before include "Pungent red salad root" , "Edible small root" , "Pungent, red salad vegetable" , "Root vegetable used in salads" , "Daikon or mooli" .)