ven·ti·la·tion (v?n?tl-??sh?n)n.1. a. The replacement of stale or noxious air with fresh air.b. The mechanical system or equipment used to circulate air or to replace stale air with fresh air.2. See respiration.3. a. The maintenance of breathing by artificial means.b. A breath that is induced by artificial means.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.ventilation (?v?nt??le???n) n1. the act or process of ventilating or the state of being ventilated2. (Building) an installation in a building that provides a supply of fresh air ?venti?lative adj ?venti?latory adjCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014ven?ti?la?tion (?v?n tl?e? ??n) n. 1. the act of ventilating or the state of being ventilated. 2. facilities or equipment for providing ventilation. [1425?75; late Middle English