The word "孩儿" is formed through semantic compounding and colloquial fusion. It combines the core character "孩" (hái), meaning "child", with the suffix "儿" (ér), which in this context acts as a diminutive or familiarizing element, commonly used in northern dialects. This fusion doesn't create a new meaning but intensifies and personalizes the original concept, resulting in a term that conveys a sense of "child" with added intimacy, affection, or informal regional flavor, akin to "little one" or "my child".