سَيّالٌ
1.
[Flowing, or running, much]. One says, نَزَلْنَا بِوَاد ٍ نَبْتُهُ مَيَّالٌ وَمَاوءُهُ سَيَّالٌ [We alighted in a valley the herbage whereof was inclining much, by reason of its luxuriant growth, and the water whereof was flowing, or running, much, by reason of its copiousness]. (TA.)
2.
[And Distilling much: see رَنْدٌ.]
3.
Also A certain mode of calculation. (O, K, TA. [In the CK, الحِيتَانْ is erroneously put for الحِسَابِ.])