baleen vs sperm whale

baleen

noun
  • A baleen whale, 

  • The keratinous material that makes up the plates in the mouth of the baleen whale, Mysticeti, which it uses to trap its food; formerly used in corsetry. 

sperm whale

noun
  • A whale (Physeter catodon, syn. Physeter macrocephalus), the largest of the toothed whales. 

  • Any whale in the superfamily Physeteroidea, which also includes the small whales of genus Kogia. 

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