Dictionary entry

Hypocycloid

Webster's Dictionary 1913

Hy′po‐cy″cloid (?), n. [Pref. hypo- + cycloid: cf. F. hypocycloïde.] (Geom.) 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.