derivational

This term is primarily used within the specialized fields of linguistics and morphology. It describes the specific mechanism of word-building where an affix is added to a root to create a new lexeme, often shifting the word from one part of speech to another, such as turning the verb "govern" into the noun "government."

It is frequently contrasted with "inflectional" morphology. While inflectional changes (like adding -s for plurality) modify a word to fit a grammatical context without changing its core meaning or category, derivational changes create entirely new words with distinct semantic identities.