Final answer:
Vomit is the most commonly aspirated material, meaning it is inhaled into the lungs instead of being swallowed.
Step-by-step explanation:
The most commonly aspirated material is vomit. Aspiration occurs when foreign material, such as vomit, enters the lungs by being inhaled rather than being swallowed into the stomach. This can happen during instances of choking, anesthesia, or when a person is unconscious.