Final answer:
Sputum is a term used in biology and medicine to refer to the mucus expelled from the respiratory tract. It can be analyzed to diagnose respiratory infections.
Step-by-step explanation:
Word: sputum
Sputum is a term used in biology and medicine to refer to the mucus that is expelled from the respiratory tract through coughing or clearing the throat. It is produced by the respiratory system and contains mucus, debris, and sometimes bacteria or other microorganisms. Sputum can be analyzed in the laboratory to diagnose respiratory infections, such as tuberculosis or pneumonia.