derivational

/ˌdɛrəˈveɪʃənəl/
adjective
  1. Relating to the process of forming a new word from an existing word by adding a prefix or suffix, often changing the word's part of speech or meaning.
    • In English, adding '-ness' to 'happy' to form 'happiness' is a derivational process.
    • Derivational morphology helps speakers create new words like 'teacher' from 'teach'.
    • The teacher explained that 'un-' is a derivational prefix because it changes the meaning of 'kind' to 'unkind'.
Antonyms
What does "derivational" mean? | whatsthatwordmean | whatsthatwordmean