Rulers' reservations after expression of disapproval (5)
I believe the answer is:
kings
'rulers'' is the definition.
(king is a kind of ruler)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for kings that I've seen before include "Men promoted" , "Honours" , "Not subjects among those" , "Either of two OT books" , "feature of 21/23 [NATIVITY SCENE]" .)