epicycloid

• POS: Noun
• HYPHEN: ep=i=cy=cloid

CIDE DICTIONARY

epicycloid, n. [Epicycle + -oid: cf. F. épicycloïde.].

 A curve traced by a point in the circumference of a circle which rolls on the convex side of a fixed circle.  [1913 Webster]
" Any point rigidly connected with the rolling circle, but not in its circumference, traces a curve called an epitrochoid. The curve traced by a point in the circumference of the rolling circle when it rolls on the concave side of a fixed circle is called a hypocycloid; the curve traced by a point rigidly connected with the rolling circle in this case, but not its circumference, is called a hypotrochoid. All the curves mentioned above belong to the class class called roulettes or trochoids. See Trochoid."  [1913 Webster]

OXFORD DICTIONARY

epicycloid, n. Math. a curve traced by a point on the circumference of a circle rolling on the exterior of another circle.

Derivative

epicycloidal adj.

ROGET THESAURUS

epicycloid

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.