Plenum

[plee-nuh m, plen-uh m] /ˈpli nəm, ˈplɛn əm/

noun, plural plenums, plena
[plee-nuh, plen-uh] /ˈpli nə, ˈplɛn ə/ (Show IPA)
1.
the state or a space in which a gas, usually air, is contained at a pressure greater than atmospheric pressure.
2.
a full assembly, as a joint legislative assembly.
3.
a space, usually above a ceiling or below a floor, that can serve as a receiving chamber for air that has been heated or cooled to be distributed to inhabited areas.
4.
the whole of space regarded as being filled with matter (opposed to ).
/ˈpliːnəm/
noun (pl) -nums, -na (-nə)
1.
an enclosure containing gas at a higher pressure than the surrounding environment
2.
a fully attended meeting or assembly, esp of a legislative body
3.
(esp in the philosophy of the Stoics) space regarded as filled with matter Compare vacuum (sense 1)
4.
the condition or quality of being full
n.

1670s, “filled space” (opposite of vacuum), from Latin plenum (spatium) “full (space),” neuter of adjective plenus “complete, full” (see plenary). The meaning “of a full assembly of legislators” is first recorded 1772.

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Plenum cable
hardware Cable that can be (legally) installed in the plenum (the space between a ceiling and the floor above it). Such cable is (usually) teflon-coated so that it will not give off toxic fumes when burned. In some parts of the world such cable is required by law. (1996-08-25)
Plenum-chamber
noun 1. a system of mechanical ventilation in which fresh air is forced into the spaces to be ventilated from a chamber (plenum chamber) at a pressure slightly higher than atmospheric pressure, so as to expel foul air.
Plenum system
noun 1. a type of air-conditioning system in which air is passed into a room at a pressure greater than atmospheric pressure

Plenum-ventilation
noun 1. a system of mechanical ventilation in which fresh air is forced into the spaces to be ventilated from a chamber (plenum chamber) at a pressure slightly higher than atmospheric pressure, so as to expel foul air.
Pleo-
1. a combining form meaning “more,” used in the formation of compound words: pleomorphism. combining form 1. a variant of plio- pleochroism, pleomorphism see pleio-. pleo- or pleio- pref. More: pleocytosis.