A more thorough explanation:

Incidenter

Incidenter means "incidentally" in Latin. It refers to something that happens by chance or as a side effect.

• During the excavation of the ancient ruins, the archaeologists found a small statue of a goddess. Incidenter, they also discovered a hidden chamber filled with treasure.
• While on a walk in the park, I incidenter ran into an old friend from high school.

The examples show how something unexpected or unplanned can happen incidenter. In the first example, the archaeologists were not looking for treasure, but they found it incidenter while excavating the ruins. In the second example, the person did not plan to meet their old friend, but it happened incidenter while they were out for a walk.