Added 10 October 2026 superellipse noun Categories: Obscure Words noun ! Definition from Wiktionary (CC BY-SA). More about superellipse at Wordnik → Where our words come from → a geometric shape constituting a transition between a rectangle and a circle; a closed curve, of which the circle and ellipse are special cases, whose parametric equation is x = a.cost, y = b.cost Related Words: hyperellipsesupercircleellipseellipsoidelliptoidellipticellipsisobroundhyperellipsoidexcircleellipticityexradius Back to today's word