Jug or churn (4)
I believe the answer is:
stir
I believe this clue is a double definition.
'jug' is the first definition.
(I've seen this before)
'churn' is the second definition.
(thesaurus)
'or' is the link.
(Other definitions for stir that I've seen before include "Excite emotionally" , "Whisk or rotate" , "Mix or agitate" , "unrest" , "Move around - prison" .)