The word "头等舱" (tóu děng cāng) is formed through a logical, descriptive compound structure common in Chinese, where "头" (tóu) means "head" or "first", "等" (děng) means "class" or "grade", and "舱" (cāng) means "cabin" or "compartment", combining to create the specific term for "first-class cabin", typically on an airplane or ship, by sequentially denoting its top ranking and physical space.