
1) Complete assembly 2) Full assembly 3) Full legislative assembly 4) Fully attended meeting 5) Fully-attended meeting 6) Meeting 7) More than a quorum 8) Opposite of a vacuum 9) Opposite of vacuum 10) State of the Union attendance 
Found on 
https://www.crosswordclues.com/clue/plenum

1) Materiality 
Found on 
https://www.crosswordclues.com/clue/plenum

space completely filled with matter
Found on 
http://phrontistery.info/p.html

• (n.) A condition, as in an occupied room, in which the pressure of the air is greater than that of the outside atmosphere; as, a plenum may exist in a hall ventilated by a fan blower. • (n.) That state in which every part of space is supposed to be full of matter; -- opposed to vacuum.
Found on 
http://thinkexist.com/dictionary/meaning/plenum/

A space between the aquarium bottom and substrate, created by supporting the substrate above the bottom using UGF plates or some other support structure. Used to keep Nitrate levels low in a saltwater aquarium. Water and organic waste diffuses down into the plenum where the wastes concentrate. Nitrifying bacteria in the upper levels of the substrat...
Found on 
http://www.aquahobby.com/articles/e_glossary.php

The ceiling plenum is the volume defined by the area above the back of the ceiling tile, and below the bottom of the structural slab above. Within this plenum is usually found a combination of HVAC ducts, electrical and electronic conduits, water pipes, traditional masking sound speakers, etc
Found on 
http://www.armstrong.com/commceilingsna/article22542.html

Space above a false ceiling in an office area where heat ducts and cables may be run. Plenum cabling is special fire resistant cabling required for use in these areas due to fire hazards.
Found on 
http://www.comptechdoc.org/independent/networking/cert/netterms.html

The space between a hanging ceiling and the floor above or roof; it usually contains HVAC ducts, electrical wiring, fire suppression system piping, etc.
Found on 
http://www.daviddarling.info/encyclopedia/P/AE_plenum.html

The space between a hanging ceiling and the floor above or roof; usually contains HVAC ducts, electrical wiring, fire suppression system piping, etc.
Found on 
http://www.electromn.com/glossary/p.htm

The air handing space between walls, under structural floors, and above drop ceilings, which can be used to route intrabuilding cabling.
Found on 
http://www.encyclo.co.uk/visitor-contributions.php
 Ple'num  noun
Ple'num  noun [ Latin , from 
 plenus full.] That state in which every part of space is supposed to be full of matter; -- opposed to 
 vacuum . 
 G. Francis. Found on 
http://www.encyclo.co.uk/webster/P/106

- The main hot-air supply duct leading from a furnace.
Found on 
http://www.homebuildingmanual.com/Glossary.htm

The area at the base of the windshield where the wipers are parked.
Found on 
http://www.translationdirectory.com/glossaries/glossary255.php

[
n] - an enclosed space in which the air pressure is higher than outside
Found on 
http://www.webdictionary.co.uk/definition.php?query=plenum
 noun
 noun an enclosed space in which the air pressure is higher than outside
Found on 
https://www.encyclo.co.uk/local/20974

The main hot-air supply duct leading from a furnace.
Found on 
https://www.encyclo.co.uk/local/22400

The space between a hanging ceiling and the floor above or roof; usually contains HVAC ducts, electrical wiring, fire suppression system piping, etc.
Found on 
https://www.encyclo.co.uk/local/22819

The main hot-air supply duct leading from a furnace.
Found on 
https://www.homebuildingmanual.com/Glossary.htm
  No exact match found.