occupying a socioeconomic position intermediate between those of the lower classes and the wealthy
a collection of things sharing a common attribute
a body of students who are taught together
people having the same social, economic, or educational status
education imparted in a series of lessons or meetings
a league ranked by quality
the bags of letters and packages that are transported by the postal service
the system whereby messages are transmitted via the post office
indicating the beginning unit in a series