'Half-moon' definitions:

Definition of 'half-moon'

From: WordNet
noun
The crescent-shaped area at the base of the human fingernail [syn: half-moon, lunula, lunule]
noun
The time at which the Moon is at first or last quarter when half its face is illuminated

Definition of 'Half-moon'

From: GCIDE
  • Half-moon \Half"-moon`\ (-m[=oo]n`), 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 (C[ae]siosoma Californiense). The body is ovate, blackish above, blue or gray below. Called also medialuna. [1913 Webster]

Definition of 'half-moon'

From: GCIDE
  • 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. [1913 Webster]