The Chinese word "坚贞不渝" is formed by combining two conceptual pairs: the first two characters, 坚 (meaning firm or steadfast) and 贞 (meaning loyal or faithful), together denote resolute fidelity; the last two characters, 不 (meaning not) and 渝 (meaning to change or alter), negate any possibility of change. This four-character idiom structurally links these pairs to express the complete idea of being unwaveringly loyal and never changing.