sector vs torus

sector

noun
  • part of a circle, extending to the center; circular sector 

  • section 

  • a fictional region of space designated for navigational or governance purposes. 

  • a field of economic activity 

  • A fixed, continuous section of the track, such that sectors do not overlap but all sectors make up the whole track. 

  • A toothed gear whose face is the arc of a circle. 

  • an area designated by boundaries within which a unit operates, and for which it is responsible 

  • zone (designated area). 

  • one of the subdivisions of a coastal frontier 

  • an instrument consisting of two rulers of equal length joined by a hinge. 

  • An area of a crag, consisting of various routes 

  • fixed-sized unit (traditionally 512 bytes) of sequential data stored on a track of a digital medium (compare to block) 

torus

noun
  • A topological space which is a product of two circles. 

  • The thickening of a membrane closing a wood-cell pit (as of gymnosperm tracheids) having the secondary cell wall arched over the pit cavity. 

  • A rounded ridge of bone or muscle, especially one on the occipital bone. 

  • {{lb|en|topology|in combination|n-torus|4-torus|etc.}} The product of the specified number of circles. 

  • A large convex molding, typically semicircular in cross section, which commonly projects at the base of a column and above the plinth. 

  • The end of the peduncle or flower stalk to which the floral parts (or in the Asteraceae, the florets of a flower head) are attached. 

  • A ring-shaped object, especially a large ring-shaped chamber used in physical research. 

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