arch vs pontoon

arch

noun
  • An architectural element having the shape of an arch 

  • An inverted U shape. 

  • Any place covered by an arch; an archway. 

  • Curved part of the bottom of a foot. 

  • A natural arch-shaped opening in a rock mass. 

  • An arch-shaped arrangement of trapezoidal stones, designed to redistribute downward force outward. 

adj
  • principal; primary 

  • knowing, clever, mischievous 

verb
  • To form into an arch shape. 

  • To cover with an arch or arches. 

pontoon

noun
  • A bridge with floating supports. 

  • A lighter or barge used for loading or unloading ships. 

  • A float of a seaplane. 

  • A card game in which the object is to obtain cards whose value adds up to, or nearly to, 21 but not exceed it. 

  • A box used to raise a sunken vessel. 

  • A flat-bottomed boat or other floating structure used as a buoyant support for a temporary bridge, dock or landing stage. 

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