What is the material that expelled from lungs called?

The material that is expelled from the lungs is called sputum. Sputum is a mixture of mucus, saliva, and other particles that are produced in the respiratory tract. It can be clear, white, yellow, or green in colour, and it can be thick or thin in consistency. Sputum is often produced when a person is coughing or sneezing, and it can be used to diagnose and treat respiratory conditions such as pneumonia, bronchitis, and asthma.