derivasional

Derivasional is an adjective used in some linguistic and philological writings to describe processes related to derivation. In this sense, it concerns the formation of new words or new grammatical categories from existing forms through systematic operations such as affixation, conversion, or compounding. Derivation typically changes a word's part of speech and semantic content, as opposed to inflection, which marks grammatical features without creating a new lexical item.

The term derives from derivation and the adjective-forming suffix -al and appears most often as a translation variant in non-English scholarship. In standard English-language usage, the preferred term is derivational. When derivasional is used, it is usually as a near-synonym or to reflect a non-English source; it is not widely standardized in major reference works.

In linguistics, derivasional processes include affixation (for example, forming teacher from teach), derivational suffixes and prefixes, and sometimes changes via conversion (noun from verb without affix). These processes typically produce words with new meanings and sometimes different grammatical categories, contributing to lexical productivity and language evolution.

Note that outside linguistics, the term is uncommon; in mathematics and related fields the familiar terms are derivative or derivation rather than derivasional. Related concepts include derivational morphology, inflection, and word formation productivity.