ceiling diffuser, ceiling outlet
1.Any air diffuser (usually round, square, rectangular, or linear) which is located in the ceiling; used to provide a horizontal distribution pattern of air over a zone occupied by people.
1.A ceiling diffuser.
2. A small metal box, mounted at ceiling level, in which electric conductors terminate; used to support a lighting fixture or other ceiling-mounted electric appliance.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.