Ⅰ.
business class UK US noun
► [U] TRANSPORT a type of air travel that is more expensive and has better conditions than economy class, or the part of a plane where people who have booked this type of travel sit: »
Most of the special deals on flights are for business class only.
»Complimentary drinks will be served to passengers in business class.
»business-class passengers/seats/tickets
► [C] a set of classes or a course of study in which the principles or methods of business are taught: »
He got a promotion after taking business classes in the evening.
► [C or U] MANAGEMENT the group of people within society who own or have important positions in companies: »
During the election campaign, the Republican Party lost support among the business class.
Ⅱ.
business class UK US adverb
► TRANSPORT in business class: fly/travel business class »
I prefer to fly business class.
Financial and business terms. 2012.