first class

nouns

the highest rank in a classification
first class
is a type of (narrower)
the quality of being superior
high quality, superiority
mail that includes letters and postcards and packages sealed against inspection
1st class, 1st-class mail, first class, first-class mail
the most expensive accommodations on a ship or train or plane
first class
is a type of (narrower)
living quarters provided for public convenience
"overnight accommodations are available"
accommodation

adverbs

by first class conveyance; with first class accommodations
"we always travel first class"
first class