Dictionary entry

Hypotrochoid

Webster's Dictionary 1913

Hy′po‐tro″choid (?), n. [Pref. hypo- + trochoid.] (Geom.) A curve, traced by a point in the radius, or radius produced, of a circle which rolls upon the concave side of a fixed circle. See Hypocycloid, Epicycloid, and Trochoid.