In
linguistics an
accidental gap, also known as a
gap,
lexical gap,
lacuna, or a
hole in the pattern, is a word or other form that does not exist in some language but which would be permitted by the
grammatical rules of the language. Accidental gaps differ from systematic gaps, those words or other forms which do not exist in a language due to the boundaries set by phonological, morphological, and other rules of that specific language.