Class  —n. 1 any set of persons or things grouped together, or graded or differentiated from others esp. By quality (first class; economy class). 2 division or order of society (upper class). 3 colloq. Distinction, high quality. 4 a group of students taught together. B occasion when they meet. C their course of instruction. 5 division of candidates by merit in an examination. 6 biol. Next grouping of organisms below a division or phylum. —v. Assign to a class or category.  in a class of (or on) its (or one's) own unequalled.  classless adj. [latin classis assembly]