reign
n
1 the period during which a monarch is the official ruler of a country
2 a period during which a person or thing is dominant, influential, or powerful
the reign of violence is over
vb intr
3 to exercise the power and authority of a sovereign
4 to be accorded the rank and title of a sovereign without having ruling authority, as in a constitutional monarchy
5 to predominate; prevail
a land where darkness reigns
6 usually present participle to be the most recent winner of a competition, contest, etc. the reigning heavyweight champion (C13: from Old French reigne, from Latin regnum kingdom, from rex king) Reign is sometimes wrongly written for rein in certain phrases: he gave full rein (not reign) to his feelings; it will be necessary to rein in (not reign in) public spending
Reign of Terror
n the period of Jacobin rule during the French Revolution, during which thousands of people were executed for treason (Oct. 1793--July 1794)