D defs.my
Entry 1 sense Webster, 1913

Hypocycloid

· Hy·po·cy·cloid · IPA
01 n. A curve traced by a point in the circumference of a circle which rolls on the concave side in the fixed circle. Cf. Epicycloid, and Trochoid.
  1. 1.
    A curve traced by a point in the circumference of a circle which rolls on the concave side in the fixed circle. Cf. Epicycloid, and Trochoid.(Geom.) See: Epicycloid, Trochoid