رِجَامٌ
1.
i. q. مِرْجَاسٌ; (S, K;) i. e. A stone which is tied to the end of a rope, and which is then let down into a well, and stirs up its black mud, after which the water is drawn forth, and thus the well is cleansed: (TA:) sometimes it is tied to the extremity of the cross piece of wood of the bucket, in order that it may descend more quickly. (S, K.)
2.
Also A thing that is constructed over a well, and across which is then placed the piece of wood for the bucket. (AA, K.) And [the dual] رِجَامَانِ
Two pieces of wood that are set up over a well, (S, K, TA,) at its head [or mouth], (S, TA,) and upon which is set the pulley, (S, K, TA,) or some similar thing by means of which one draws the water. (TA.)