Potential lexicon

Potential lexicon is a term used for the unbounded list of potential words, where 'potential word' is defined as any word form that can be generated by the word formation rules of a language. Hence, the potential lexicon contains the actual or attested words plus the potential, but not attested words.

Example
in English, the potential lexicon contains actual words such as approve, approval, recite, recital, derive, and describe, and the potential words *derival and *describal.

Links
Utrecht Lexicon of Linguistics