دور

دَيْرٌ دير , originally with و; (T, S;) or originally thus, with ى, (M, [and so accord. to the place in which it is mentioned in the A and Msb and K,]) as appears from the occurrence of the ى in its pl. and in the derivative دَيَّارٌ, for if the ى were in this case interchangeable with و it would occur in other derivatives; (M;) [or this is not a valid reason, for دَيَّارٌ is held by J to be originally دَيْوَارٌ, i. e. of the measure فَيْعَالٌ; and ISd himself seems in one place to express the same opinion; in like manner as دَيُّورٌ is held by the latter to be originally دَيْوُورٌ; and تَدَيَّرَ is evidently altered from تَدَوَّرَ;] A convent, or monastery, (خان,) of Christians: (M, K:) and also the صَوْمَعَة [i. e. cloister, or cell, ] of a monk: (A:) the pl. is أَدْيَارٌ (S, M, K) and دُيُورَةٌ. (Msb.) ― -b2- [Hence,] رأْسُ الدَّيْرِ [lit. The head of the convent or monastery ] is an appellation given to (tropical:) Any one who has become the head, or chief, of his companions. (IAar, S, A, K.)