mollusc vs pullet

mollusc

noun
  • A weak-willed person. 

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

pullet

noun
  • A spineless person; a coward. 

  • A young hen, especially one less than a year old. 

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