hyperboloid
noun
hy·per·bo·loid hī-ˈpər-bə-ˌlȯid 
: a quadric surface whose sections by planes parallel to one coordinate plane are ellipses while those sections by planes parallel to the other two are hyperbolas if proper orientation of the axes is assumed
hyperboloidal
(ˌ)hī-ˌpər-bə-ˈlȯi-dᵊl
adjective 
Example Sentences
Recent Examples on the Web Not one but two tall monoliths now overlook the harbor: William Zeckendorf’s rooftop airport covers a substantial fraction of Manhattan’s western edge, and I.M. Pei’s pinch-waisted hyperboloid rises a hundred stories above Grand Central Terminal. 
Will Heinrich, New York Times, 21 Sep. 2017
Will Heinrich, New York Times, 21 Sep. 2017 Word History
First Known Use
1743, in the meaning defined above