(ن) دَرَسَ يَدْرُسُ دَرْسًا وَدِرَاسَةًdarasa yadrusu darsan wa-dirāsatan: this root has two basic aspects, both springing from one origin: (1) to efface the trace of something, and intransitively, for traces to be effaced (hence دَرَسَ الرَّسْمُdarasa ar-rasm = the traces of the ruins were effaced); (2) to read a book repeatedly and study it. The lexicographers say the first sense is contained in this in that repeated reading wears the page down, or that the reader passes over the letters again and again as a foot passes over the ground. ﴿وَدَرَسُوْا مَا فِيْهِ﴾ (Al-Aʿrāf 7:169); ﴿وَبِمَا كُنْتُمْ تَدْرُسُوْنَ﴾ (Āl ʿImrān 3:79)
Form III (mufāʿalah) دَارَسَ يُدَارِسُ مُدَارَسَةًdārasa yudārisu mudārasatan: to read together, to teach one another / to learn from someone. ﴿وَلِيَقُوْلُوْا دَرَسْتَ﴾ (Al-Anʿām 6:105) (in one reading "دَارَسْتَdārasta")Form II (tafʿīl) دَرَّسَ يُدَرِّسُ تَدْرِيْسًاdarrasa yudarrisu tadrīsan: to teach, to instruct.
مِدْرَاسٌmidrās / مَدْرَسَةٌmadrasah: a place of study.