Improvised cigar stuffed with pound of old vegetable (6)
I believe the answer is:
garlic
'vegetable' is the definition.
(I've seen this before)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for garlic that I've seen before include "Pungent bulbs" , "Food flavouring not favoured by vampires?" , "Aromatic bulb used as seasoning" , "Pungent cooking ingredient" , "Kitchen additive" .)