ventilation

noun

1. 1

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

2. 2

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

3. 3

   a mechanical system in a building that provides fresh air

   she was continually adjusting the ventilation

4. 4

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

   such a proposal deserves thorough public discussion