Similar word to classes:

branch, brand, breed, cast, caste, character, classification, collection, color, degree, denomination, department, description, designation, distinction, division, domain, estate, family, feather, frame, genre, genus, grade, grain, grouping, hierarchy, humor, ilk, kidney, league, make, mold, name, nature, order, origin, property, province, quality, range, rank, rate, school, sect, section, selection, set, source, species, sphere, standing, status, stripe, style, suit, temperament, value, variety


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