Vegetable, you can make speed out of it (6)
I believe the answer is:
celery
'vegetable' is the definition.
(celery is a kind of vegetable)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for celery that I've seen before include "Vegetable in sticks" , "Salad plant, in sticks" , "Plant with edible stems" , "Plant with edible stalks" , "Its leaf stalks are used in salads or as a vegetable" .)