overfullness vs plenum

overfullness

noun
  • The state of being excessively or abnormally full. 

plenum

noun
  • A state of fullness, a great quantity (of something). 

  • An enclosed space having greater than atmospheric pressure. 

  • The space above a false ceiling used for cables, ducts etc. 

  • A type of network cabling which satisfies plenum-ratings issued by the National Electrical Code. These cables produce less smoke and fumes in the event of fire. 

  • A legislative meeting (especially of the Communist Party) in which all members are present. 

  • A space that is completely filled with matter. 

How often have the words overfullness and plenum occurred in a corpus of books? (source: Google Ngram Viewer )