[hahy-puh-sahy-kloid] 
| a curve generated by the motion of a point on the circumference of a circle that rolls internally, without slipping, on a given circle. |
hypocycloid (hī'pō-sī'kloid') Pronunciation Key
(click for larger image in new window) The curve described by a point on the circumference of a circle as the circle rolls on the inside of the circumference of a second, fixed circle. |
pəˈsaɪ