J. Daniel Hays

“The word “canon” is derived from a Hebrew word signifying “reed” (qaneh) and by extension “measuring stick.” It enters into the Greek language as “canon” (kanon) with a wider semantic range signifying exemplary standards in relation to literary works, grammatical rules, and even certain human beings. The word was coined in the early church to indicate an absolutely authoritative, complete list of God-inspired books, which was the standard of truth (Athanasius, 39th Festal Letter). Although such a list was considered closed, it is clear that the creation of the canon did not happen in an instant. It had a long and complex history before such closure occurred. The historian Josephus (AD 95) describes a closed list of inspired books that had been authoritative for all Jews for centuries (Against Apion 8).”
― J. Daniel Hays, How the Bible Came to Be