Word

A word is the smallest unit of language that can stand alone with a distinct meaning and function within sentences. Words combine to form phrases and sentences, convey ideas, identify objects, actions, qualities, or relations, and can express grammatical relations through inflection or word order.

Most languages classify words into lexical categories such as nouns, verbs, adjectives, and adverbs, and function words such as pronouns, prepositions, conjunctions, determiners, and particles. Words are subject to morphology, producing different forms (for example, dogs, dog’s, walked). Some languages rely on affixes, others use word order for grammar, and some use compounding to create new words.

The term originates from Old English word “word,” from Proto-Germanic roots; cognates include Dutch woord and German Wort. The concept predates writing, but writing systems use distinct scripts and conventions to encode words, including spaces in many languages to delimit word boundaries.

In lexicography, words are entries with definitions, usage notes, and inflections. In natural language processing, a word is a token, and tokenization is the process of splitting text into words; many NLP applications also work with subword units or embeddings to handle rare or compound words.

Words can shift in meaning, acquire new senses, or form new compounds over time, a phenomenon called semantic change and productivity of word formation.