Suctioning means using a device to remove liquid or air from something, like a person's mouth or a machine.
Suctioning is often used in medical situations to help people breathe or to clean out their mouths.
Examples:
The nurse is suctioning the patient's mouth.
Suctioning helps people breathe better.
We need to do suctioning on the machine.
The doctor showed me how to do suctioning.
The suctioning machine is very loud.
I don't like the feeling of suctioning in my mouth.