a very important day, especially for a particular person or group Saturday promises to be a big day for Irish sport. 星期六将是爱尔兰体育运动的重要一天。 The children enjoyed themselves preparing for their big day. 孩子们喜欢为自己的大日子做准备。
a person's wedding day Her family travelled to Australia for the big day. 她的家人前往澳大利亚度过了重要的一天。