Collins Chinese Dictionary Plus (3rd edition), 2011:
之一 zhī yī 代
one of
- 他是他们(們)班最用功的学(學)生之一。 Tā shì tāmen bān zuì yònggōng de xuésheng zhī yī. He is one of the hardest working students in their class.
- 沈阳(陽)是中国(國)最大的城市之一。 Shěnyáng shì Zhōngguó zuì dà de chéngshì zhī yī. Shenyang is one of China's biggest cities.