Definition & Meaning of "open-class word"in English

What is an "open-class word"?

An open-class word is a word that belongs to a grammatical category with a relatively unlimited number of members, allowing for the addition of new words as language evolves. These words typically include nouns, verbs, adjectives, and adverbs. Unlike closed-class words, which have a fixed set of members, open-class words can readily accept new additions, reflecting changes in culture, technology, and other areas of life. Understanding open-class words is essential for vocabulary development and effective communication, as they provide the content and meaning in sentences.