res·pi·ra·tor (r?s?p?-r??t?r)n.1. See ventilator.2. A device worn over the mouth or nose or both to protect the respiratory tract from harmful dust or fumes.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.respirator (?r?sp??re?t?) n1. (Medicine) an apparatus for providing long-term artificial respiration2. Also called: gas mask a device worn over the mouth and nose to prevent inhalation of noxious fumes or to warm cold air before it is breathedCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014res?pi?ra?tor (?r?s p??re? t?r) n. 1. an apparatus to produce artificial respiration. 2. a filtering device worn over the nose and mouth to prevent inhalation of noxious substances. [1830?40] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.respiratorA machine that maintains regular breathing by pumping air in and out of the lungs.Dictionary of Unfamiliar Words by Diagram Group Copyright © 2008 by Diagram Visual Information Limited