What does classifier mean?
A classifier is a person or thing that sorts items into categories according to shared characteristics. The word applies across several domains: a classifier may be a professional — for example, someone who catalogues specimens, artworks, or library materials — or, increasingly, an algorithm or program that automatically assigns data to classes, as in machine learning systems that label images or filter email. In linguistics, a classifier is a small word or affix required when counting or specifying certain nouns, indicating the semantic category of the item counted; languages such as Mandarin Chinese and Japanese make extensive use of them, so a speaker must choose a form appropriate to flat objects, animals, long thin things, and so on. Derived from the verb 'classify', the noun carries a neutral, technical tone and appears frequently in academic, computational, and information-science writing.
A person or thing that classifies; especially a person employed to sort items into categories, or an algorithm that assigns items to classes.
"The postal service once employed hundreds of classifiers to route letters by hand."
In computing contexts, often modified by terms such as 'binary' or 'statistical'.
In linguistics, a word or morpheme used with numerals or demonstratives to indicate the semantic class of the noun being counted or specified.
"Mandarin uses the classifier 本 (běn) when counting books, as in sān běn shū, 'three volumes of books'."
Regular plural. Commonly used when discussing multiple algorithms or the classifier systems of particular languages.
"Modern languages vary widely in how many classifiers they require in everyday speech."
In Mandarin you can't just say 'three books' — you need a classifier word in between, making these little counting words one of the most distinctive features of the world's languages.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of classifier
Classifier derives from the verb classify, which entered English in the early 17th century from Medieval Latin classificare, built on Latin classis, meaning a group, division, or fleet. The agent-noun suffix -er was added to form classifier, denoting one who classifies. It shares its root with related words such as classic and classification, all tracing back to that same Latin source.
How classifier is actually used
Neutral register. In everyday use it usually refers to people or software; the linguistic sense is technical but well established in grammar descriptions of East Asian and other classifier languages.
Easily confused with classifier
A clarifier is something that makes a substance or explanation clearer (or a device that removes impurities from liquid), whereas a classifier sorts things into categories.