Coincidence (noun)

1. A remarkable concurrence of events or circumstances without apparent causal connection.
2. The occurrence of events that happen at the same time by accident but seem to have some connection.

Origin:

From latin co- "together" + incidere "to fall".

Examples:

1. It was just a coincidence that they met at the train station.
2. The coincidence of their meeting was too much of a coincidence to ignore.
3. It was a coincidence that they both wore the same outfit.
4. The coincidence of the two events happening at the same time was astounding.
5. The coincidence of the two people having the same name was just a coincidence.