calamus vs feather pen

calamus

noun
  • A quill; the hard, horny, hollow, and more or less transparent part of the stem or scape of a feather. 

  • Synonym of fistula (“tube for sucking Eucharist wine”) 

  • A palm in genus Calamus, of rattan palms. 

  • The sweet flag, Acorus calamus. 

  • A fish of genus Calamus in family Sparidae; certain porgies. 

feather pen

noun
  • A quill. 

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