mollusc vs servant

mollusc

noun
  • A weak-willed person. 

  • A soft-bodied invertebrate of the phylum Mollusca, typically with a hard shell of one or more pieces. 

servant

noun
  • A person of low condition or spirit. 

  • One who serves another, providing help in some manner. 

  • A person who dedicates themselves to God. 

  • One who is hired to perform regular household or other duties, and receives compensation. As opposed to a slave. 

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