reign

noun

1. royal power, authority, or rule; sovereignty
2. dominance, prevalence, or sway: the reign of good will
3. the period of rule, dominance, sway, etc.

intransitive verb

1. 1. to rule as a sovereign
   2. to hold the title of sovereign, as in a constitutional monarchy
2. to hold sway; prevail or predominate: when peace reigns