n. V形棱堡

Ravelin \Rave"lin\ (r[a^]v"l[i^]n; 277), n. [F.; cf. Sp.
rebellin, It. revellino, rivellino; perhaps fr. L. re- again
+ vallum wall.] (Fort.)
A detached work with two embankments which make a salient
angle. It is raised before the curtain on the counterscarp of
the place. Formerly called {demilune} and {half-moon}.

Half-moon \Half"-moon`\ (-m[=oo]n`), 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}.