encircling vs roundel

encircling

noun
  • encirclement 

adj
  • enclosing, skirting 

roundel

noun
  • A bastion of a circular form. 

  • A circular insignia painted on an aircraft to identify its nationality or service. 

  • A small circular shield, sometimes not more than a foot in diameter, used by soldiers in the fourteenth and fifteenth centuries. 

  • Anything having a round form; a round figure; a circle. 

  • A circular spot; a charge in the form of a small coloured circle. 

  • A roundelay or rondelay. 

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