The term 'Reign Over' can be broken down into four crossword solutions: GOVERN (6 letters), RULE (4 letters), OWN (3 letters), and DOMINATE (8 letters). To 'GOVERN' means to exercise authority over a state or other political unit, while 'RULE' is to exercise power or authority over someone or something. To 'OWN' is to have legal possession of something, and to 'DOMINATE' is to have control or influence over something. Taken together, the term 'Reign Over' implies having complete control and authority over something.