vain / Ñ veIn; NAmE Ñ / adjective 1that does not produce the result you want SYN useless:She closed her eyes tightly in a vain attempt to hold back the tears. Ç I knocked loudly in the vain hope that someone might answer.2(disapproving) too proud of your own appearance, abilities or achievements SYN conceited:She’s too vain to wear glasses.—see also vanity(这是牛津最新版上的解释,希望你能看得懂!)