If habits or ideas ossify, or if something ossifies them, they become fixed and unable to change.

Years of easy success had ossified the company's thinking and it never faced up to the challenge of the new technology. 多年来轻易取得的成功让这家公司变得思维僵化，从不直面新技术带来的挑战。

If body tissue ossifies, it becomes hard and changes into bone.