مَسِيلٌ

A place [or channel] in which a torrent flows: (Msb:) or مَسِيلُ مَاءٍ and مَاءٍ ↓ مَسَلُ, (S, K,) the latter anomalous, so much so that a parallel to it is scarcely, or in no wise, known, (MF,) a water-course; i. e. a place [or channel] in which water flows, or runs: plural [of pauc., of the former,] أَمْسِلَةٌ, (S, K,) and [of mult.] مَسَايِلُ and مُسُلٌ; and مُسْلَانٌ; (S, Msb, K, TA;) the second plural regular, without ء, (TA, [though written in the CK with ء,]) and the rest irregular, (S, * TA,) the singular being likened to رِغِيفٌ, (S, Msb, TA,) which has for its plural أَرْغِفَةٌ and رُغُفٌ (S, TA) and رُغْفَانٌ. (S, Msb, TA.)

It is also a verbal noun (TA. [See 1, first sentence.])

Also Rain causing much flowing; opposed to مَزْرَغٌ [q. v.]. (Ham p. 632.) [See also what follows.]