The word 坚定 is formed by combining two independent characters, each carrying a core conceptual meaning, to create a new, unified idea. The first character, 坚 (jiān), embodies the concept of solidity, hardness, and unyielding strength, like a rock. The second, 定 (dìng), embodies the concept of stability, steadiness, and being settled or decided. Their union is not merely additive but synergistic, fusing the metaphorical solidity of 坚 with the resolute steadiness of 定 to produce the complete concept of being "firm and determined", where physical metaphor conveys a state of mental or moral resolve.