plenary

adjective

ple·​na·​ry ˈple-nə-rē 

also

ˈplē- 

1

: complete in every respect : absolute, unqualified

plenary power

2

: fully attended or constituted by all entitled to be present

a plenary session

Did you know?

In the 14th century, the monk Robert of Brunne described a situation in which all the knights of King Arthur's Round Table were present at court by writing, "When Arthures court was plener, and alle were comen, fer and ner.…" For many years, plener (also spelled plenar) served English well for both senses that we reserve for plenary today. But we'd borrowed plener from Anglo-French, and, although the French had relied on Latin plenus ("full") for their word, the revival of interest in the Classics during the English Renaissance led scholars to prefer purer Latin origins. In the 15th century, English speakers turned to Late Latin plenarius and came up with plenary. (Plenarius also comes from plenus, which is the source of our plenty and replenish as well.)

Synonyms

• entire
• whole
• full
• complete
• comprehensive
• total
• perfect

Choose the Right Synonym for plenary

full, complete, plenary, replete mean containing all that is wanted or needed or possible.

full implies the presence or inclusion of everything that is wanted or required by something or that can be held, contained, or attained by it.

a full schedule

complete applies when all that is needed is present.

a complete picture of the situation

plenary adds to complete the implication of fullness without qualification.

given plenary power

replete implies being filled to the brim or to satiety.

replete with delightful details

Examples of plenary in a Sentence

A plenary meeting of the 500 members was held last summer.

plenary sessions of the legislature

Recent Examples on the Web

Bian Zhigang, vice administrator of the China National Space Administration (CNSA), was asked about what challenges this ramp-up poses for long-term sustainability in space at the International Astronautical Congress in Sydney, Australia, during a Heads of Agencies plenary session on Sept. 29. —Andrew Jones, Space.com, 7 Oct. 2025

Russian President Vladimir Putin speaks during an annual plenary session of the Valdai Discussion Club, on October 2, 2025 in Sochi, Russia. —Sam Meredith, CNBC, 3 Oct. 2025

In order to win a war—especially a war that threatened the nation’s very existence—the federal government enjoyed plenary power to liberate slaves, as nations at war had commonly done long before the Constitution was drafted and ratified. —Akhil Reed Amar, Time, 22 Sep. 2025

The festival’s opening and plenary session, which will be attended by of HRH Princess Astrid of Belgium, will host Minister-President Matthias Diependaele. —Dade Hayes, Deadline, 17 Sep. 2025

Word History

Etymology

Middle English plenarie, borrowed from Late Latin plēnārius, from Latin plēnus "full" + -ārius -ary entry 2 — more at full entry 1

First Known Use

15th century, in the meaning defined at sense 1

Phrases Containing plenary

• plenary indulgence

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Kids Definition

plenary

adjective

ple·​na·​ry ˈplē-nə-rē  ˈplen-ə- 

1

: complete in all ways : full

plenary powers

2

: including all who have a right to attend

a plenary session of an assembly

Legal Definition

plenary

adjective

ple·​na·​ry ˈplē-nə-rē, ˈple- 

: full and complete in every respect: as

a

: absolute sense 1

plenary power

b

: fully attended or constituted

a plenary session of the legislature

c

: including all steps in due order

a plenary proceeding

compare summary