Definition of "plenum" [ple•num]

• An assembly or meeting with all members present. (noun)
• A condition, space, or enclosure in which air or other gas is at a pressure greater than that of the outside atmosphere. (noun)
• The condition of being full; fullness. (noun)
• A space completely filled with matter. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "But it is more usual to employ what is called the plenum process, in which air under high pressure is pumped into the caisson and expels the water, as in a diving bell."
• "The air runs through a massive bank of modular filters to remove dust and other contaminants before it circulates in a massive cavity, called a plenum, below its data center halls."
• "The flow typically proceeds from the throttle body into a chamber called the plenum, which in turn feeds individual tubes, called runners, leading to each intake port."