Definition of "good-bye"

“I can’t come back, my dear,” called Oz from the basket. “Good-bye!” / “Good-bye!” shouted everyone, and all eyes were turned upward to where the Wizard was riding in the basket, rising every moment farther and farther into the sky.

1900 May 17, L[yman] Frank Baum, “How the Balloon was Launched”, in The Wonderful Wizard of Oz, Chicago, Ill., New York, N.Y.: Geo[rge] M. Hill Co., pages 207–208

At the door I turned for a final good-bye, but I clammed up when I noticed Adrienne’s thoughtful expression.

2006, Ginny Aiken, Decorating Schemes (Deadly Décor Mysteries; 2), Grand Rapids, Mich.: Revell, page 128