Rules
'rules' is the definition.
(reign can mean to rule or govern)
This is the entire clue.
(Other definitions for reigns that I've seen before include "Rules as monarch" , "Holds sway" , "Rules as sovereign" , "Singer who governs" , "Obtains" .)
'rules' is the definition.
('govern' can be a synonym of 'rule')
This is the entire clue.
(Another definition for governs that I've seen is " Rules".)
'rules' is the definition.
(laws are rules)
This is the entire clue.
(Other definitions for laws that I've seen before include "Rules imposed by authority" , "Rules, statutes" , "Regulations" , "Codes of action" , "code" .)