This is the 13491st most frequent Spanish word.
regir
"Regir" means "to govern, rule, or regulate."
Here, 'regir' is used to mean 'governing or regulating,' referring to a legal or authoritative framework in operation.
Las leyes que rigen este país garantizan la igualdad.
The laws that govern this country ensure equality.
In this case, 'regir' is used reflexively ('se rige') to signify that one's behavior is guided or influenced systematically by specified principles.
Su comportamiento siempre se rige por principios éticos.
His behavior is always guided by ethical principles.
Here, 'regir' encapsulates the notion of control or governance attributed to cosmic or astrological elements in people's lives.