I think it's an invented word from a piece of literature whose title I can't remember. Another roleplayer mentioned it to me. It means the tendency of a place to hold the most negative emotions that human beings have ever radiated while interacting in that place. I've been thinking about my childhood recently, and it seems to me that the ground of the houses me and my family lived in would be rich with noirance. (But it would have the opposite, too.)
Anadem, right now, if only because it actually seems to encompass the form of a garland <3
I also love the Portuguese word for mouth, "boca". It sounds both delicate and visceral, which I find very suitable indeed.