تعد كتب النوادر من كتب اللغة لمعالجتها لبعض اللغات غير المعروفة. وكان غاية اللغويين الأولى في جمع النادر من الألفاظ هو الوصول بها إلى أفصح صورة، لذلك نجد أنهم كانوا يُقَومون بعض الآراء ويغلطونها، وكانوا يستشهدون بشواهد بين المنظوم والمنثور والشاهد القرآني في نقلهم للمادة اللغوية، وكان اللغويون في جمعهم للنادر لا يعتمدون على منهج معين وإنما كانوا ينظرون إلى المادة اللغوية ومدى ندرتها. بدأ التأليف في النوادر في بداية القرن الثاني لـلـهجرة أي مع بداية تدوين اللغة واستمر قرابة قرنين، والعلماء الذين دونوا اللغة الفصيحة هم أنفسهم مَن ألفوا في النادر؛ لأنهم جمعوا اللغة من جميع القبائل، فوجدوا أن كل ما قل استعماله، أولم يكن في استعمال العرب الموثوق بعربيتهم عَدّوه نادراً أو شاذًا. وتوقف التأليف فيه في القرن الرابع. وأول من ينسب إليه كتاب في النوادر هو أبو عمرو بن علاء (ت157هـ). جمعنا في هذه الدراسة الألفاظ النادرة في كتاب تهذيب اللغة للأزهري (ت370هـ)، وقسمناها على مبحثين الأول للدراسة وبدأناه بالمقدمة والتي تضمن بشدايات التأليف في النوادر، وثم التعريف النادر لغة واصطلاحاً، ثم التأليف في النوادر والعلماء الذين ألفوا فيه، وبعدها عرفنا بالأعراب وأصولهم، ويليها الاختلاف في مفهوم النوادر وأبرز الظواهر اللغوية التي تضمنتها ألفاظ النوادر في المعجم، ثم ختمنا الدراسة بالنتائج التي توصلنا إليها، أما المبحث الثاني فكان خاصاً بمعجم ألفاظ النوادر في تهذيب اللغة، وختمنا الدراسة بالمصادر التي اعتمدنا عليها.

Writing about language idiosyncrasies began at the same time when scholars began writing language from the mouth of relaters. They considered whatever expressions that were rarely used in their language and were not used by authenticated Arabs as rare expressions or irregular expressions. Idiosyncrasy books are considered linguistic books as they tackle some of the unknown languages. Dr. Aza Hasan is quoted in al- Nawadr Book(Idiosyncrasies Book) by Abo Mashal al-Aarabi stating that writing about language idiosyncrasies and peculiarities began in the mid of the second century A.H. i.e. the same time when language scholars began to write about the Arabic language and actively collected language corpuses which lasted for a half of century. Scholars’ involvement on writing about language idiosyncrasies increased in the third century A.H. and continued for almost a whole century to the extent that we rarely find a linguist or relater who did not write about language idiosyncrasies. Writing about linguistic idiosyncrasies faded out in the mid of the third century A.H. and it was stopped in the fourth century. Abo Amr Alaa(died in 157 A.H.) is credited for being the pioneer in writing the first idiosyncratic book. Linguists’ foremost purpose of collecting rarely used expressions was to get to the most standardized form; therefore, they sometimes appraised some expressions and sometimes considered them to be wrong. Scholars quoted instances from poetry, prose and Quranic verses as linguistic corpuses. Furthermore, linguists did not adopt any specific approach in collecting rarely used expressions but rather they would look into the linguistic material and to what extent it was rarely used. In al-Mu’jam al-Arabi(Arabic Dictionary), Dr. Husein Nassar is quoted stating,” Idiosyncratic books deal with some unknown languages and they are more like linguistic books to the extent that most of the times one cannot tell the differences between idiosyncratic and linguistic books.” Dr. Muhammad Abdulqadir states that “The examples used in the idiosyncratic books of the second century A.H. and early third century A.H., were expressions, phrases proverbs and styles that are typical of the pre-Islamic and early Islamic periods. We have found out in this study that although the nomads are unknown, and the linguistic corpuses that we collected are not attributed to a specific tribe, i.e. the scholars did not specify the sources of their corpuses. This was apparent in most idiosyncrasy books. That means the purpose idiosyncrasies books was merely to collect linguistic corpuses – which means that they were more like language books, and Dr. Muhammad Abdulqadir added that “These books did not develop in term of the approach that was adopted, but rather the scholars adhered to the same style that was adopted in the first time, and the only development that these books witnessed was proliferation and amplification.