plenum

noun

ple·​num ˈple-nəm  ˈplē- 

1

a

: a space or all space every part of which is full of matter

b

: an air-filled space in a structure

especially : one that receives air from a blower for distribution (as in a ventilation system)

2

: a general assembly of all members especially of a legislative body

3

: the quality or state of being full

Examples of plenum in a Sentence

Recent Examples on the Web

Nearly one in five Central Committee members missed the latest plenum under a political cloud, a record in China’s post-Mao era. —Neil Thomas, Time, 29 Oct. 2025

The 15th Five-Year Plan, which was announced after the fourth plenum of the 20th Communist Party Congress in Beijing last week, is viewed as a continuation of policy efforts announced last year and does not signal a paradigm shift. —Denni Hu, Footwear News, 29 Oct. 2025

The Communist Party plenum will debate China's next Five-Year Plan, the 15, setting important markers for the coming years. —Deirdre Kirsten Tatlow, MSNBC Newsweek, 21 Oct. 2025

About a dozen seats are expected to be filled by alternate members at this plenum. —Simone McCarthy, CNN Money, 20 Oct. 2025

Word History

Etymology

borrowed from Latin plēnum, noun derivative from neuter of plēnus "full"; (sense 1a) after its use in the Lucullus book of Cicero's Academica to denote a space completely filled with matter (distinguished from ināne or vacuum "empty space"); (sense 2) apparently first from its use in Sweden in the eighteenth century to refer to a meeting of all members of the Riksdag — more at full entry 1

First Known Use

1678, in the meaning defined at sense 1a

Rhymes for plenum

• denim
• venom
• imipenem