annular vs orbicular

annular

adj
  • Pertaining to, or having the form of, a ring; ring-shaped; in the shape of an annulus. 

  • Banded or marked with circles. 

orbicular

adj
  • Circular or spherical in shape; round. 

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