\Lune\, n. [L. luna moon: cf. F. lune. See {Luna}.]
1. Anything in the shape of a half moon. [R.]

2. (Geom.) 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. [Obs.]

         These dangerous, unsafe lunes i' the king. --Shak.