1. Anything in the shape of a half moon.
2. (Science: geometry) a figure in the form of a crescent, bounded by two intersecting arcs of circles.
3. A fit of lunacy or madness; a period of frenzy; a crazy or unreasonable freak. These dangerous, unsafe lunes i the king. (Shak)
Origin: L. Luna moon: cf. F. Lune. See luna.