Sailor has no vegetable (4)
I believe the answer is:
taro
'vegetable' is the definition.
(I know that taro is a type of List of root vegetables)
'sailor has no' is the wordplay.
'sailor' becomes 'tar' (slang term for a sailor).
'has' says to put letters next to each other.
'no' becomes 'o' (resembles 0 - 'no' can mean 'zero').
'tar'+'o'='TARO'
(Other definitions for taro that I've seen before include "A rot turns the lily-like plant" , "Fortune-telling cards" , "Root to eat" , "Starchy plant" , "Shortly pack" .)