plenums

Noun

plenum (plural plenums or plena)

1. A space that is completely filled with matter.
   • The idea was that a thing could only move into an empty place, and that, in a plenum, there are no empty places.1946, Bertrand Russell, A History of Western Philosophy

   Antonyms:

   vacuum

2. (figuratively) A state of fullness, a great quantity (of something).
   • He lay on the long stone slant down to the slapping waves, his denim shorts, sneakers, and socks under his head for a pillow, feeling the splendour of distance in all directions, the liquid silence, the plenum of aloneness.1974, Guy Davenport, Tatlin!
3. A legislative meeting (especially of the Communist Party) in which all members are present.
4. An enclosed space having greater than atmospheric pressure.
5. The space above a false ceiling used for cables, ducts etc.
6. A type of network cabling which satisfies a given plenum rating for the purpose of fire safety.