diadem vs orle

diadem

noun
  • An ornamental headband worn as a badge of royalty. 

  • Regal power; sovereignty; empire—considered as symbolized by the crown. 

  • A crown. 

  • An arch rising from the rim of a crown (rarely also of a coronet), and uniting with others over its centre. 

verb
  • To adorn with a diadem; to crown. 

orle

noun
  • The wreath, or chaplet, surmounting or encircling the helmet of a knight and bearing the crest; a torse. 

  • A fillet under the ovolo of a capital. 

  • A bordure that runs around the outline of a shield without touching the edge. 

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