pier vs piling

pier

noun
  • A raised platform built from the shore out over water, supported on piles; used to secure, or provide access to shipping; a jetty. 

  • A structure supporting the junction between two spans of a bridge. 

  • A similar structure, especially at a seaside resort, used to provide entertainment. 

  • A rectangular pillar, or similar structure, that supports an arch, wall or roof, or the hinges of a gate. 

piling

noun
  • A structural support comprising a length of wood, steel, or other construction material. 

  • The act of heaping up. 

  • The process of building up, heating, and working fagots or piles to form bars, etc. 

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