The word **橙子** (chéngzi), meaning "orange" (the fruit), is formed through a common Mandarin morphological process where the core noun **橙** (chéng), which originally denotes both the orange tree and its fruit/color, is combined with the suffix **子** (zi). This suffix **子** often serves as a nominalizer, adding no specific meaning but frequently used to form disyllabic words from monosyllabic roots, making speech flow more rhythmically and sometimes distinguishing a concrete object (like the fruit) from other meanings. In this case, **橙子** specifically refers to the edible fruit, while **橙** alone can be more ambiguous, referring to the color or the tree. This pattern is consistent with many other fruit names in Chinese, such as 桃子 (táozi, peach) and 李子 (lǐzi, plum).