molehead vs quay

molehead

noun
  • A stone bulwark forming a haven or harbour; a breakwater. 

quay

noun
  • A stone or concrete structure on navigable water used for loading and unloading vessels; a wharf. 

verb
  • To land or tie up at a quay or similar structure, especially used in the phrase "quay up". 

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