Coincident describes any group of people, moments, or ideas that seem to work together so perfectly that it’s spooky or beautiful, like it’s part of a big logical plan.
Coincident is a mix of the prefix co- (meaning “together” and “similar”) and an incident, which means "a noteworthy event." So when you have two similar noteworthy events that happen together, they are coincident with one other. Professional dancers have dance moves coincident with one another. If you immediately know the answer to a question your teacher asks, your knowledge is coincident with the lessons being taught. Congrats, smarty pants.