Chanciness is the noun for being chancy: not certain, with a lot of risk still in it, so luck still has a big say. A plan, a journey, or a deal has chanciness when you cannot really count on the result. Weather, late buses, and anything that hangs on one person’s mood all have this quality. The word is a little more writerly than just saying “it’s risky” or “it’s chancy”; you meet it in careful prose more than in everyday chat. Underneath it is chance — not a plan, but a throw of the dice. It is about uncertainty and risk, not about churches or law courts.