conch vs sea slug

conch

noun
  • A marine gastropod of the family Strombidae which lives in its own spiral shell. 

  • A musical instrument made from a large spiral seashell, somewhat like a trumpet. 

  • The shell of this sea animal. 

  • Synonym of concher (“machine used to refine the flavour and texture of chocolate”) 

  • The semidome of an apse, or the apse itself. 

verb
  • To refine the flavour and texture of chocolate by warming and grinding, either in a traditional concher, or between rollers. 

  • To play a conch seashell as a musical instrument, by blowing through a hole made close to the origin of the spiral. 

sea slug

noun
  • Any soft-bodied marine gastropod mollusks of the order Nudibranchia. 

  • A common name for any marine invertebrate with a visual resemblance to terrestrial slugs (land slugs). 

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