Definition of "Ventilation" :

noun: the act of supplying fresh air and getting rid of foul air

noun: the bodily process of inhalation and exhalation; the process of taking in oxygen from inhaled air and releasing carbon dioxide by exhalation

noun: a mechanical system in a building that provides fresh air

"She was continually adjusting the ventilation."

noun: free and open discussion of (or debate on) some question of public interest