The word **池子 (chízi)** is formed through a common Mandarin nominalization pattern where the core character **池 (chí)**, meaning "pond" or "pool," is combined with the suffix **子 (zi)**, which serves to form a concrete, everyday noun. While **池** alone can denote the general concept, adding **子** creates a more colloquial and familiar term, often implying a smaller, more specific, or man-made feature like a residential pond, a bathing pool, or even a modern swimming pool. This **root + 子** structure is highly productive in Chinese, with the suffix **子** typically adding no independent meaning but functioning grammatically to mark the word as a tangible, everyday object.