from The American Heritage® Dictionary of the English Language, 4th Edition
- n. An assembly or meeting with all members present.
- n. A condition, space, or enclosure in which air or other gas is at a pressure greater than that of the outside atmosphere.
- n. The condition of being full; fullness.
- n. A space completely filled with matter.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A space that is completely filled with matter.
- n. A state of fullness, a great quantity (of something).
- n. A legislative meeting (especially of the Communist Party) in which all members are present.
- n. An enclosed space having greater than atmospheric pressure.
- n. The space above a false ceiling used for cables, ducts etc.
- n. A type of network cabling which satisfies plenum-ratings issued by the National Electrical Code. These cables are safer in case of a fire, producing less smoke and fumes.
from the GNU version of the Collaborative International Dictionary of English
- n. That state in which every part of space is supposed to be full of matter; -- opposed to
- n. A condition, as in an occupied room, in which the pressure of the air is greater than that of the outside atmosphere.
from The Century Dictionary and Cyclopedia
- n. The fullness of matter in space: the opposite of vacuum: also used to denote fullness in general.
- n. A quantity of a gaseous body in an inclosed space greater than would remain there under normal atmospheric pressure.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. an enclosed space in which the air pressure is higher than outside
- n. a meeting of a legislative body at which all members are present
Latin plēnum (spatium), full (space), neuter of plēnus.(American Heritage® Dictionary of the English Language, Fourth Edition)
From Latin plēnum, noun use of neuter of plēnus ("full"). Influenced by Russian пленум (plénum, "plenary session"), from the same Latin source. (Wiktionary)