The word 笼子 is formed by combining the character 笼, which carries the core meaning of "cage" or "basket-like enclosure", with the character 子, which here functions not as an independent word but as a nominal suffix. This suffix 子 is commonly attached to nouns, often to indicate a concrete, physical object or to create a colloquial, everyday term. Thus, the root meaning of "enclosure" from 笼 is concretized and finalized into the specific, common noun for a physical "cage" or "container".