ellipsoid vs oblong

ellipsoid

adj
  • Shaped like an ellipse; elliptical. 

  • Having the tridimensional shape of an ellipse rotated on its long axis. 

  • Of or pertaining to an ellipse; elliptic. 

noun
  • A surface, all of whose cross sections are elliptic or circular (including the sphere), that generalises the ellipse and in Cartesian coordinates (x, y, z) is a quadric with equation x²/a² + y²/b² + z²/c² = 1. 

  • Such a surface used as a model of the shape of the earth. 

oblong

adj
  • Roughly rectangular or elliptical. 

  • Having the horizontal axis of a page longer than the vertical; In landscape orientation. 

  • Having a length and width that are different; not square or circular. 

verb
  • To give an oblong shape to. 

  • To extend so as to form an oblong shape. 

noun
  • A rectangle with length and width that are different. 

  • An ellipse with minor and major axes that are different. 

  • Something with an oblong shape. 

How often have the words ellipsoid and oblong occurred in a corpus of books? (source: Google Ngram Viewer )