ˌfirst-ˈclass BrE AmE adjective
1 . of very good quality, and much better than other things of the same type:
This is a first-class wine.
His writing is first-class.
2 . relating to the class of post that is the most expensive and quickest to arrive
first-class stamp/mail/post etc
3 . relating to the best and most expensive class of seats on a plane or train, or rooms in a hotel
first-class passenger/seat/compartment etc
—first class adverb :
If I send the letter first class it should arrive tomorrow.
travel first class