Plenum

Part of speech: noun

Pronunciation: /ˈpliːnəm/

Definitions

1. A space or chamber that is completely filled with matter, or a full assembly of all members of a governing body
2. A space that contains matter in its entirety, or an assembly gathering all members of a group for discussion and decision-making
3. An area fully occupied by substance or a meeting of all stakeholders involved in a decision-making process

Etymology: The English noun "plenum" began as a plain Latin term for a space packed completely with matter, with no empty room left over. The Latin "plēnum" is the neuter form of "plēnus," meaning "full," so the word's original sense is simply "that which is full." Its use in physics and engineering, for an enclosed space filled with air or gas at a set pressure, keeps that literal meaning intact. The word's most surprising turn comes from Russia. The sense "legislative meeting," as in a full session of a governing body where every member gathers, was borrowed into English as a semantic loan from Russian "пленум" (plenum, "plenary session"). Russian took the Latin word and gave it a political meaning, and English then adopted that meaning, so the political sense reached English by way of Russia rather than directly from Latin.

Synonyms: fullness, completeness

Antonyms: vacuum, emptiness