compost vs guano

compost

noun
  • The decayed remains of organic matter that has rotted into a natural fertilizer. 

  • A medium in which one can cultivate plants. 

verb
  • To produce compost, let organic matter decay into fertilizer. 

guano

noun
  • Coccothrinax borhidiana, a variety of palm tree indigenous to Cuba. 

  • Dung from a sea bird or from a bat. 

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