hypocycloid Syllabification: (hy·po·cy·cloid)Pronunciation: /ˌhīpəˈsīˌkloid/Definition of hypocycloid noun Mathematics the curve traced by a point on the circumference of a circle that is rolling on the interior of another circle. Derivatives hypocycloidalPronunciation: /ˌhīpəˈsīˌkloidl/ adjective hypocycloid in other Oxford dictionaries Definition of hypocycloid in the British & World English dictionary