As nouns the difference between sputum and spitoon
is that sputum is (physiology) matter coughed up and expectorated from the mouth, composed of saliva and discharges from the respiratory passages such as mucus, phlegm or pus while spitoon is .
(physiology) Matter coughed up and expectorated from the mouth, composed of saliva and discharges from the respiratory passages such as mucus, phlegm or pus.