plenary

The word "plenary" originates from the Late Latin term plēnārius, meaning "complete" or "full," which itself derives from the classical Latin adjective plēnus (full). This Latin root can be traced further back to the Proto-Indo-European (PIE) root pelə-, meaning "to fill," a source it shares with other English words like "plenty" and "complete." The semantic journey is direct: from the literal concept of fullness, the meaning extended to describe meetings attended by the full membership and, by further abstraction, to denote absolute or unqualified authority or condition.

Structure: plen (full) + ary (adjective suffix) plen (from Latin plēnus, meaning "full"); ary (a suffix forming adjectives, from Latin -ārius, indicating "pertaining to" or "connected with").