‘Jī dàn’ literally means ‘chicken egg’—it combines 鸡 (jī), meaning ‘chicken’, and 蛋 (dàn), meaning ‘egg’. While Chinese has general terms for ‘egg’ (e.g., 蛋), 鸡蛋 specifically refers to eggs laid by chickens, the most common edible egg in daily life. It is a countable noun used frequently in cooking, shopping, nutrition discussions, and household contexts.

This word appears in many everyday expressions: in recipes (e.g., ‘add two eggs’), at markets (‘How much for one dozen eggs?’), and in idioms (e.g., 鸡蛋碰石头, ‘an egg hitting a stone’—a futile effort). Unlike some other animal eggs (like 鸭蛋 yādàn ‘duck egg’ or 鹅蛋 édàn ‘goose egg’), 鸡蛋 is so ubiquitous that it’s often shortened to just 蛋 in informal speech when context is clear—though strictly speaking, 蛋 alone is generic and can refer to any egg.