1 in the best group; of the highest standard 最优良的；第一流的: a first-class player 第一流的球员 [SYN] excellent 同义词为excellent

2 giving or using the best and most expensive type of service 头等；提供或使用最佳、最昂贵服务的: Ten first-class stamps, please. 请给我十枚第一类邮票。first-class rail travel 乘头等车厢的火车旅行

3 (only before a noun 只用于名词前) used to describe a university degree of the highest class from a British university （英国大学）一等学位的: She was awarded a first-class degree in French. 她获得法语一等学位。