circumscribe vs mullion

circumscribe

verb
  • To draw a line around; to encircle. 

  • To limit narrowly; to restrict. 

  • To draw the smallest circle or higher-dimensional sphere that has (a polyhedron, polygon, etc.) in its interior. 

mullion

verb
  • To shape into divisions by means of mullions. 

noun
  • A vertical bar between the panes of glass or casements of a window or the panels of a screen. 

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