The Chinese idiom 马失前蹄 is formed by sequentially combining the characters 马 (horse), 失 (to lose), 前 (front), and 蹄 (hoof), creating a literal meaning of "a horse losing its front hoof". This construction directly depicts a specific physical scenario, which then serves as a metaphor for an unexpected mishap or error caused by negligence. Each character contributes to the immediate visual and conceptual basis for the figurative expression.