Half-moon

·noun The shape of a half-moon; a crescent.

II. Half-moon ·noun The moon at the quarters, when half its disk appears illuminated.

III. Half-moon ·noun An outwork composed of two faces, forming a salient angle whose gorge resembles a half-moon;

— now called a ravelin.

IV. Half-moon ·noun A marine, sparoid, food fish of California (Caesiosoma Californiense). The body is ovate, blackish above, blue or gray below. Called also medialuna.