encircling vs spherical

encircling

adj
  • enclosing, skirting 

noun
  • encirclement 

spherical

adj
  • Of, or pertaining to, spheres. 

  • Shaped like a sphere. 

  • Of or relating to the heavenly orbs, or to the sphere or spheres in which, according to ancient astronomy and astrology, they were set. 

  • Of a coordinate system, specifying the location of a point in a plane by using a radius and two angles. 

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