Sederunts are formal meetings where people talk about important things.
Sederunts are usually serious and important.
Examples:
The sederunts lasted for hours.
The sederunts discussed the new rules.
At the sederunts, they made big decisions.
The sederunts were so long, I fell asleep.
In the sederunts, they talked about very big things.
The sederunts were very boring.