1. The quality or state of occurring or existing at the same time
The simultaneity of the two events was remarkable.
A simultaneidade dos dois eventos foi notável.
2. In physics and relativity theory, the concept that events can occur at the same time in different reference frames
Einstein's theory challenges our understanding of simultaneity.
A teoria de Einstein desafia nossa compreensão da simultaneidade.
3. The act or condition of happening together or at once
The simultaneity of their arrivals was purely coincidental.
A simultaneidade de suas chegadas foi puramente coincidência.