IPA: /ˈplɛnəm/
KK: /ˈplɛnəm/
A space or condition where air or gas is at a higher pressure than the surrounding atmosphere, or a meeting where all members are present.
The engineers discussed the design of the ventilation system in the plenum.
Plenum comes from the Latin word "plenus" (meaning full). It refers to a state of fullness or completeness, often used in contexts such as meetings or discussions where all members are present and contributing.
Think of 'full' in Latin ('plenus') to remember that 'plenum' means a state of fullness or completeness.