From Longman Dictionary of Contemporary Englishsputumspu‧tum /ˈspjuːtəm/ noun [uncountable] medicalHBHMI liquid in your mouth which you have coughed up from your lungs → phlegm
Examples from the Corpus
sputum• A sputum pot and tissues should be provided if appropriate and steam inhalations may be ordered.• The rare acute infection shows dyspnoea and violent cough, with white-yellow, occasionally bloody, sputum.• Gao Yang noticed a frothy string of bloody sputum at the corner of his mouth and felt sorry for the sharp-tongued fellow.• In some patients, there was four-fold increase in antibody response before the first sputum culture of P cepacia.• Repeated microbiological examination of sputum, blood, and urine proved negative.• Blood stained sputum, salty, sour or yellow.• The sputum had decreased and for two successive tests had been negative.• Patients M24, M25, and M26 were inpatients when the epidemic strain was first cultured from their sputum.Origin sputum (1600-1700) Latin spuere “to spit” 