Which term refers to a state of being open and clear, free from obstruction?

The term "patent" directly refers to a state of being open and clear, free from obstruction. In medical terminology, this is often used to describe airways or blood vessels that are unobstructed and allow for the free passage of air or blood. For example, when assessing a patient, an EMT may check if the airway is patent, indicating that it is clear and functioning properly.

It's also important to note that "patency" is closely related to "patent," but it refers to the condition or quality of being open and unobstructed, rather than being an adjective describing the state itself. "Viable" typically refers to the ability of tissues or cells to survive or function effectively, while "clearance" can pertain to the removal of substances from the bloodstream or respiratory system but does not specifically denote a state of being free from obstruction in the same way "patent" does.