What is the term for the amount of air breathed out after a normal breath?

The correct term for the amount of air breathed out after a normal breath is tidal volume. Tidal volume refers to the volume of air inhaled and exhaled during a regular, relaxed breath. When we breathe normally, we take in a certain amount of air, and the same amount is expelled in the following exhalation, which defines tidal volume.

Conversely, expiratory reserve volume represents the additional amount of air that can be forcibly exhaled after the completion of a normal exhalation. Total lung capacity is the total volume of air that the lungs can hold after a maximal inhalation, which includes all lung volumes. Inspiratory reserve volume refers to the additional air that can be inhaled after a normal inhalation. Each of these terms signifies different aspects of lung function, but in the context of the question, tidal volume is the appropriate descriptor for a normal breath's exhaled air.