Work muddled dean with king (5)
I believe the answer is:
Here is my best explanation:
'work' is the definition.
('knead' can be a synonym of 'work')
'muddled dean with king' is the subsidiary indication.
'muddled' indicates an anagram.
'with' says to put letters next to each other.
'king' becomes 'k' (**).
'dean' with letters rearranged gives 'nead'.
'nead' put after 'k' is 'knead'.
(Other definitions for knead that I've seen before include "Work (dough) into mass", "Pummel dough", "Manipulate", "Massage with hands", "Massage - naked (anag)", "Naked (anag.)", "Work (dough/clay)", "Work with finger movements", "Work dough or massage flesh" and "Work flour into dough manually".)