void for vagueness

void for vagueness adj. referring to a statute defining a crime which is so vague that a reasonable person of at least average intelligence could not determine what elements constitute the crime. Such a vague statute is unconstitutional on the basis that a defendant could not defend against a charge of a crime which he/she could not understand, and thus would be denied "due process" mandated by 5th Amendment, applied to the states by the 14th Amendment.