first class

first-class的词性：
n.（名词）

1. The first, highest, or best group in a system of classification:
一级，甲等，一流：在分类系统中最先的、最高的或最好的：

a restaurant of the first class.
第一流的餐馆

2. The most luxurious and most expensive class of accommodations on a train, passenger ship, airplane, or other conveyance.
头等舱：火车、客轮、飞机或其它运载工具中最豪华、最昂贵的住宿等级

3. A class of mail including letters, post cards, and packages sealed against inspection.
优先投递，第一类：包括信件、明信片和包裹等密封起来免检的一类邮件

first-class

first-class的音标和读音：
DJ音标发音： [ˈfə:stˈklæs]
KK音标发音： [ˈfɜstˈklæs]

first-class的词性：
adj.（形容词）

1. Constituting or belonging to the first, highest, or best group in a system of classification:
一流的，甲等的：构成或属于一个分类系统中最先的、最高的或最好一组的：

a first-class hotel; first-class mail.
一家一流的旅馆；一类邮件

2. Of the foremost excellence or highest quality; first-rate:
极好的，一流的：最优秀的或质量最高的；最高等级的：

a first-class mind.
一颗高尚的心

first-class的词性：
adv.（副词）