Definition of "unbelieving"

One Sunday morning I woke up, saying to my sister N., " Do you know, I have had such a vivid dream about the Roper party that I can hardly believe T am awake now." "What did you dream?" said N., in rather an unbelieving and sleepy tone of voice.

1887, Harriet W. Daly, Digging, Squatting, and Pioneering Life in the Northern Territory of South Australia, page 105

The burnt and bleeding man staggered to his feet, dazed and unbelieving, and asked the startled townspeople who came running whether his fireman and guard were safe. He was kept away from the smouldering crater where his engine had been, and taken to hospital.

2022 January 12, Benedict le Vay, “The heroes of Soham...”, in RAIL, number 948, page 43