THESAURUS
semicircle
crescent, crescent moon, fifty percent, fifty-fifty, half, half circle, half-and-half, half-moon, hemicycle, hemisphere, horseshoe, lunula, lunule, mediety, meniscus, moiety, quadrant, scythe, sector, semisphere, sextant, sickle
ROGET THESAURUS
semicircle
Circularity
N
circularity, roundness, rotundity, circle, circlet, ring, areola, hoop, roundlet, annulus, annulet, bracelet, armlet, ringlet, eye, loop, wheel, cycle, orb, orbit, rundle, zone, belt, cordon, band, contrate wheel, crown wheel, hub, nave, sash, girdle, cestus, cincture, baldric, fillet, fascia, wreath, garland, crown, corona, coronet, chaplet, snood, necklace, collar, noose, lasso, lassoo, ellipse, oval, ovule, ellipsoid, cycloid, epicycloid, epicycle,
semicircle, quadrant, sextant, sector, sphere, round, rounded, circular, annular, orbicular, oval, ovate, elliptic, elliptical, egg-shaped, pear-shaped, cycloidal, spherical, I watched the little circles die.