Happenstance
Part of speech: noun
Definition: A chance or random event or circumstance. The chance or random quality of an event or circumstance.
Example sentence: What is the one country in the Middle East that has not been attacked by ISIS? One. That is Iran. That is more than happenstance, I'm sure.
Coincidence
Part of speech: noun
Definition: Of objects, the property of being coincident; occurring at the same time or place.Of events, the appearance of a meaningful connection when there is none.A coincidence point.
Example sentence: I part-own a bookshop for some strange coincidence of reasons, and it is one of the best things I part-own in my life, or own in my life. I do not know, it just feels great.