A reversion to a previous state, system, or kind of behaviour is a change back to it.
例句
This is a reversion to the system under which the Royals were paid for nearly 300 years.又恢复了旧时的体制，王室就是在这种制度下接受了近300年的俸禄。...a reversion to the emotions of her baby years.她向婴儿期情感的回归
N-VAR
(土地或财产的)归还
The reversion of land or property to a person, family, or country is the return to them of the ownership or control of the land or property.