Actually, that’s not my definition. It’s the standard definition that I saw in both Galvin and Tanenbaum. I copy pasted that definition from Tanenbaum.
Let’s say there is a set of four processes, {P1, P2, P3, P4}.
Here,
P1 is waiting for release_R2 which can be caused by P2
P2 is waiting for release_R3 which can be caused by P3
P3 is waiting for release_R1 which can be caused by P1
and
P4 is waiting for release_R1 too which can be caused by only P1
Every process in this set is waiting for an event(release event) that only another process in the set can cause.
Therefore, By definition, this set is a set of deadlocked processes, Where P1, P2, and P3 have caused that deadlock by participating in circular wait condition.