The New Testament word for church is ekklesia, and it was originally used to describe an assembly of citizens who were “called out” by a herald. The biblical meaning, then, is a group of earthly people who have been called out by Christ for his purposes.
The Zondervan Pictorial Encyclopedia of the Bible, Volume 1, ed. Merrill C. Tenney (Grand Rapids: Zondervan, 1976), 845-846
Hayes, J. (2009). Blemished: How The Message of Malachi Confronts Empty Religion (p. 14). Nashville, TN: LifeWay Press.