The story
coined in: M. Laurent and S. Poljak, On a positive semidefinite relaxation of the cut polytope, Linear Algebra Appl., 223/224, (1995), 439-461
Etymology from Wiktionary, CC BY-SA 4.0.
elliptope
Today it means: The set of all real, square symmetric matrices whose diagonal entries are all equal to one and whose eigenvalues are all non-negative. Full definition →