spittle vs sputum

spittle

noun
  • Spit-up or drool of an infant. 

  • Spit, usually frothy and of a milky coloration. 

  • A small sort of spade. 

  • Something frothy and white that resembles spit. 

verb
  • To dig or stir with a small spade. 

sputum

noun
  • Matter coughed up and expectorated from the mouth, composed of saliva and discharges from the respiratory passages such as mucus, phlegm or pus. 

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