The word "锈迹" is formed by combining the character "锈", meaning rust, which itself is composed of the metal radical "钅" to indicate its relation to metal and the component "秀" to suggest its pronunciation, with the character "迹", meaning trace or mark, derived from elements conveying the idea of a remnant or impression. Together, they create a compound where "锈" specifies the type of mark, resulting in the meaning of rust traces.