The basic definition of “canon” is rule, standard, or norm. It derives from a Semitic word which meant reed, cane, stalk of grain. “The idea of measurement became predominant and from the 5th cent. B.C. kanon meant above all a measuring line, measuring rod, balance arm, fixed rule, norm.”
In the New Testament “canon” is used by Paul only in 2 Corinthians 10:13, 15, 16 and Galatians 6:16. It is used in contexts where it has the meaning of norm, rule, or standard.
But the word “canon” has a technical meaning as well. Colin Brown defines canon as “…the list of writings recognized by the church as documents of divine revelation.” Notice what Brown says. The church recognized these writings as divine revelation and, therefore, authoritative. Andrew Walls says, “…the list of writings accepted as authoritative and binding.” The books were accepted as authoritative and binding not made so by the church. And Brian H. Edwards says, “…a collection of books that are fixed in their number, divine in their origin and universal in their authority.”
The canon of the New Testament has come to mean the list of twenty-seven inspired, authoritative, apostolically approved books which comprise our New Testament. Canon does not refer to an authoritative list of books but to the list of authoritative books. The books are authoritative, not because they are listed or not because of who listed them, but because they were inspired by God and either written by apostles or what the early church called “apostolic men.” They do not gain authority from men; they gain their authority from God and, therefore, are authoritative and binding on the church.
 Colin Brown, “Rule, Standard, Measure” in Colin Brown, Editor, The New International Dictionary of New Testament Theology, Volume 3 (Grand Rapids: Zondervan, 1986), 399.
 Brown, “Rule, Standard, Measure,” 399.
 Brown, “Rule, Standard, Measure,” 400.
 Andrew F. Walls, “The Canon of the New Testament” in EBC, 1:631.
 Brian H. Edwards, Why 27? (Darlington, England: Evangelical Press, 2007), 26.