Half-moon

n. 1. The moon at the quarters, when half its disk appears illuminated. [ 1913 Webster ]

2. The shape of a half-moon; a crescent. [ 1913 Webster ]

See how in warlike muster they appear,
In rhombs, and wedges, and half-moons, and wings. Milton. [ 1913 Webster ]

3. (Fort.) An outwork composed of two faces, forming a salient angle whose gorge resembles a half-moon; -- now called a ravelin. [ 1913 Webster ]

4. (Zool.) A marine, sparoid, food fish of California (Caesiosoma Californiense). The body is ovate, blackish above, blue or gray below. Called also medialuna. [ 1913 Webster ]