Synonyms for Half-moon:

n.

orbit, sink, rise, come up, go in, go down, eclipse, full moon, wax, wane. bulge, coil, circle, ball, bubble, bowl, balloon, band, crescent, cone. arc (noun)
crescent.
body (noun)
lunula, lunule.
curve (noun)
circle.
half-moon (noun)
lunula, lunule.
moon (noun)
full moon.

Other synonyms:

crescent. Other relevant words:
crescent, full moon.