A plenary session or meeting is attended by all members of an organization.
A plenipotentiary is someone who has full power to take action or make decisions on behalf of their government in a foreign country.
When you replenish something, you refill or restock it.
When there is a plenitude of something, there is an abundance, ample supply, or significant quantity of it.
A plentiful amount of something, such as food, is more than enough of it.
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