Akademik

first class
first-class ˌfirst-ˈclass also first class adjective
1. if something is first-class, it is of very good quality and much better than other things of the same type:

• We provide a first-class, professional service for our customers.

2. using first-class mail:

• a first-class stamp

3. TRAVEL first class seats, accommodation etc are the most comfortable and expensive available:

first-class airline tickets

• The airline claims its 9,000 daily first-class seats are 65% full.

— first class adverb :

• If you send the letter first class, it should arrive tomorrow.

• Company policy says we cannot fly first class, but we can fly business class on trips over a thousand miles.

* * *

Ⅰ.
first class UK US adjective
of excellent quality: »

The work that she did on the project was first class.

»

He really is pre-eminent in the field and has built up a first-class business.

TRANSPORT relating to the highest level of service offered on a plane, train, etc.: »

a first-class cabin/fare/seat, etc.

in the UK, relating to the fastest service for sending mail: »

It is welcome news that first-class delivery has improved.

»

The cost of a first-class stamp is going up.

in the US, relating to the service used for sending letters, cards, and small packages: »

He predicts first-class volume will decline by 20 percent by the year 2017 as fewer people sit down to write a letter.

»

Experts expect that the U.S. Postal Service soon will request a price increase for first-class letters.

used to describe the best possible degree you can get from a university in the UK: »

A report showed that a first-class degree is worth, on average, 12% more in likely future earnings.

Compare BUSINESS CLASS(Cf. ↑business class) noun, ECONOMY CLASS(Cf. ↑economy class), SECOND-CLASS(Cf. ↑second-class) adjective
Ⅱ.
first class UK US adverb
TRANSPORT using the highest level of service offered: fly/travel first class »

I fly business class; I don't fly first class.

using the fastest service for sending mail: »

The minimum requirement is that certificates must be sent first class to the shareholder's registered address.

Ⅲ.
first class UK US noun [U]
the best seats, service, etc. on a plane, train, etc.: »

I didn't see him on the flight because he was in first class.

in the UK, the fastest service for sending mail: »

Always use first class for sending these documents.

in the US, the service for sending letters, cards and small packages

Financial and business terms. 2012.