What is the term that describes the use of affixes to create new words from a root or base word?

The term that describes the use of affixes, such as prefixes and suffixes, to create new words from a root or base word is known as derivation. Derivation involves the process of adding these affixes to base words to form new words with distinct meanings or grammatical functions. For example, taking the root word "act" and adding the suffix "-ion" forms the word "action." This process expands the vocabulary and allows for the creation of a variety of related words, enhancing language complexity and expressiveness.

The other terms presented relate to different aspects of language. Lexicon refers to the vocabulary of a language or an individual's knowledge of words, but it does not specifically refer to the process of word formation. Syntax deals with the rules governing sentence structure and the arrangement of words to create coherent sentences, whereas discourse refers to large units of language beyond the sentence level, encompassing conversation, written texts, and their contexts. Understanding derivation is essential for recognizing how words are formed and how their meanings can change through affixation.