derivational

Derivational is an adjective used in linguistics to describe processes and morphemes that form new words from existing ones. In derivational morphology, affixes such as prefixes and suffixes attach to a base to create a new lexeme, often with a change of meaning and sometimes a shift in syntactic category. This contrasts with inflectional morphology, which modifies a word to express grammatical features without producing a new word.

Derivational morphemes vary in productivity and flexibility across languages. They can be highly productive, allowing speakers to coin new words, or limited to fixed lexicalized forms. Derivation can affect meaning in predictable ways and can also change the word class, such as turning a verb into a noun or an adjective.

Examples in English include:

- un- in unhappy (prefix changing a word’s polarity and meaning)

- -ness in happiness (noun formed from an adjective)

- -er in teacher (noun formed from a verb, an agentive derivation)

- -ment in development (noun formed from a verb/verb root)

- -ful in careful (adjective formed from a noun)

- -ize in modernize (verb formed from an adjective)

Some derivational processes also lead to semantic shifts or irregular outcomes, and multiple derivational steps can chain to create complex forms. Derivation is studied alongside morphology and phonology within theories that examine how words are built, how meaning is constructed, and how new terms enter a language’s lexicon.

In other disciplines, derivational may appear in reference to derivation processes in mathematics, logic, or computer science, but in linguistics it most often denotes the formation of new words through derivational morphemes.