\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.