Linguistics term for a word or morpheme used to classify nouns, such as Japanese counter words (助数詞) or Chinese classifiers.
Japanese words like 本 (hon) and 枚 (mai) are a type of classifier.
Classifiers are used to indicate the semantic category of a noun.
Compound of 類別 (ruibetsu, 'classification') + 詞 (shi, 'word; part of speech'). A modern linguistic term.