الخبير
كلمةُ (الخبير) في اللغةِ صفة مشبَّهة، مشتقة من الفعل (خبَرَ)،...
A description of a narrator who claims to have jointly listened to a particular hadith, or a part of a book, or a book of hadith with another narrator, or attributing a hadith known to have been narrated by a particular narrator to a different one belonging to the same class, or to attach a hadith text to a chain of transmission which does not belong to it. The phrase is close to the third grade of unacceptability, which means that the hadiths narrated by such people are totally unacceptable as evidence or for reconfirmation.