An effective ranking of claims or losses according to a time factor.
For example, the potential losses suffered by depositors during a bank run.
Those who withdraw their deposits first are the least likely to suffer losses.
This is one reason why bank runs can be self-perpetuating once they have started.
From an individual depositor's perspective, it is rational to withdraw a deposit once the run has begun.
(Even if the original reason for the run was not rational.)