1. An exclamatory statement of discontent, used euphemistically, in informal presence (such as friends) to express annoyance at a situation that has resulted from the friends action, from an action of the speaker, or from both.
Sorry, I couldn't find the teacher.
Creatures made up by Luna Lovegood from the Harry Potter books. They are known to live in mistletoe, and they are quite the little theves. Sometimes, Nargles are used in Draco/Luna fanfiction.
Luna: When we were five, you told me that mistletoe had nargles in them.
Draco: And you believed me?
Luna: You haven't lied to me since.