tippe top

• tippy top

Coined by Danish engineer Werner Østberg in the 1950s. (This etymology is missing or incomplete. Please add to it, or discuss it at the Etymology scriptorium.)

tippe top (plural tippe tops)

1. A spinning top of a shape with counterintuitive behaviour: generally mushroom-like or spherical, with a rounded head and a short stem; when spun head-down on a smooth, flat surface, it inverts its attitude so that it spins head-up, on the tip of the stem, until it loses momentum and falls over.
   • 2008 January, Nawaf M. Bou-Rabee, Jerrold E. Marsden, Louis A. Romero, “Dissipation-Induced Heteroclinic Orbits in Tippe Tops”, in SIAM Review‎, volume 50, number 2, →DOI, →ISSN, pages 325–344:

     On a flat surface, the tippe top will rest stably with its stem up. However, spun fast enough on its blunt end, the tippe top momentarily defies gravity, inverts, and spins on its stem until dissipation causes it to slow down and then fall over.