due process.
This portion of the Magna Carta is describing the rights a person gets when arrested and awaiting trial. This is referred to as "due process".
The Magna Carta inspired many of the laws found in the US Constitution. In the case of due process, the Fifth and Sixth Amendments address issues of arrest and trial. This passage provides protection for citizens that they will not be arrested for a frivolous reason or at the whim of a leader. It also protects the person while in jail waiting trial that they will not have to wait an undue amount of time.