The word "摸爬滚打" is formed by sequentially combining four characters, each representing a distinct physical action: 摸 (to feel or grope), 爬 (to crawl or climb), 滚 (to roll), and 打 (to hit or fight). These actions are juxtaposed to depict a series of strenuous movements, collectively conveying the literal process of engaging in rough, hands-on activities, which extends metaphorically to enduring hardships or gaining practical experience through struggle.