those people at the top of a social hierarchy / the aristocracy

occupying a position between the upper class and the working class

(A status, section, etc which is of) premier rank. / (Ireland) the third year of primary school, following after the junior and senior infant levels.

Belonging to the best or top group in a system of classification. / Of, or relating to the most luxurious and expensive class of accommodation on a train, ship, hotel, etc.

A social and economic class lying above the working class and below the upper class.

The social class of those who perform physical work for a living, as opposed to the professional or middle class, the upper class, or others.

Alternative spelling of working-class

(music) An equivalence class of all pitches that are octaves apart, and which would be labeled by an integer, not a traditional letter name.

(music) An interval measured by the distance between its two pitch classes ordered so they are as close as possible.

(US) All students who have graduated or will graduate from a school in a given year.