Source : Webster's Revised Unabridged Dictionary (1913)
Half-moon \Half"-moon`\, n.
1. The moon at the quarters, when half its disk appears
illuminated.
2. The shape of a half-moon; a crescent.
See how in warlike muster they appear, In rhombs,
and wedges, and half-moons, and wings. --Milton.
3. (Fort.) An outwork composed of two faces, forming a
salient angle whose gorge resembles a half-moon; -- now
called a {ravelin}.
4. (Zo["o]l.) A marine, sparoid, food fish of California
({C[ae]siosoma Californiense}). The body is ovate,
blackish above, blue or gray below. Called also
{medialuna}.