ventilation

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. The replacement of stale or noxious air with fresh air.
2. n. The mechanical system or equipment used to circulate air or to replace stale air with fresh air.
3. n. See respiration.
4. n. Aeration or oxygenation, as of blood.

Century Dictionary and Cyclopedia

1. n. The act of fanning or blowing.
2. n. The act or process of replacing foul or vitiated air, in any confined space, with pure air; the theory, method, or practice of supplying buildings, ships, mines, chimneys, air-shafts, etc., with pure air.
3. n. Aëration of the blood or the body by means of respiratory organs; admission of air in respiration.
4. n. The act of bringing to notice and discussion; public exposition; free discussion: as, the ventilation of abuses or grievances.
5. n. Utterance; expression; vent.

Wiktionary

1. n. The replacement of stale or noxious air with fresh.
2. n. The mechanical system used to circulate and replace air..
3. n. An exchange of views during a discussion.
4. n. The bodily process of breathing; the inhalation of air to provide oxygen, and the exhalation of spent air to remove carbon dioxide.

GNU Webster's 1913

1. n. The act of ventilating, or the state of being ventilated; the art or process of replacing foul air by that which is pure, in any inclosed place, as a house, a church, a mine, etc.; free exposure to air.
2. n. obsolete The act of refrigerating, or cooling; refrigeration.
3. n. The act of fanning, or winnowing, for the purpose of separating chaff and dust from the grain.
4. n. The act of sifting, and bringing out to view or examination; free discussion; public exposure.
5. n. The act of giving vent or expression.

WordNet 3.0

1. n. a mechanical system in a building that provides fresh air
2. n. the bodily process of inhalation and exhalation; the process of taking in oxygen from inhaled air and releasing carbon dioxide by exhalation
3. n. free and open discussion of (or debate on) some question of public interest
4. n. the act of supplying fresh air and getting rid of foul air