Various cabbages have skin disease (4)
I believe the answer is:
scab
'skin disease' is the definition.
(scab can mean an animal skin disease)
'various cabbages have' is the wordplay.
'have' indicates a hidden word.
'SCAB' is hidden in the letters of 'various cabbages'.
(Other definitions for scab that I've seen before include "cause of itch?" , "Crust of congealed blood" , "He's not out" , "evidence of recent injury" , "Scoundrel" .)