"Plenary inspiration" is a form of revelation.The Plenary Inspiration in terms of the Bible tells us that authors were infallible; they did not make any errors when they were writing the particular text because the Holy Spirit of God was working through them.

"Plenary", the final part of the traditional three part lesson

Plenary power or plenary authority, the complete power of a governing body

Plenary session or meeting, the part of a conference when all members of all parties are in attendance