folium vs leaflet

folium

noun
  • A leaf, especially a thin leaf or plate. 

  • A curve of the third order, consisting of two infinite branches having a common asymptote. The curve has a double point, and a leaf-shaped loop. 

  • Synonym of turnsole (“purple dye”) 

leaflet

noun
  • A small plant leaf. 

  • A small sheet of paper containing information, used for dissemination of said information, often an advertisement. 

  • One of the components of a compound leaf. 

  • A flap of a valve of a heart or blood vessel. 

verb
  • To distribute leaflets to. 

  • To distribute leaflets. 

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