Sometimes the words of a hadith are widely used, yet their precise import is difficult enough that an ordinary lexical definition cannot settle their meaning. In such cases one needs explanatory works on the meanings of reports and the literature of problematic hadith.
Scholars such as al-Ṭaḥāwī, al-Khaṭṭābī, and Ibn ʿAbd al-Barr contributed to this field. The question then moves beyond “What does this word mean in a dictionary?” to “What does this report convey in context, and how should it be understood in relation to other well-attested material?”
Thus rare wording and difficult meaning remain distinct. The former needs lexical explanation of an unfamiliar term; the latter needs interpretation of subtle meaning or an apparent conceptual difficulty despite familiar vocabulary.