Ventilator \Ven"ti*la`tor\, n. [Cf. F. ventilateur, L. ventilator a winnower.]

A contrivance for effecting ventilation; especially, a contrivance or machine for drawing off or expelling foul or stagnant air from any place or apartment, or for introducing that which is fresh and pure.

Source: Webster's Revised Unabridged Dictionary (1913)