Happening at the same time as something else.
Synchronal things are connected and happen together.
Examples:
The two friends had a synchronal idea at the same time.
The two clocks showed the same time, so they were synchronal.
The two cars arrived at the same time, so they were synchronal.
The two cats meowed at the same time, it was synchronal!
All the people in the world jumping at the same time would be a very synchronal event.
The two dancers moved in a synchronal way.