مَاءٌ سَجِيسٌ

Water that is altered, changed in odour, or stinking; synonym مُتَغَيِّرٌ: turbid, thick, or muddy: as also ↓ سَجِسٌ, (K, TA,) and ↓ سَجْسٌ: (TA:) or corrupted, and stirred up; as also ↓ مُسَجَّسٌ: or the last signifies made turbid, thick, or muddy, and stirred up: the [only] form mentioned in the S is ↓ سَجَسٌ: but Aboo-Sahl says that ↓ سَجِسٌ is the form learned by him in reading under Aboo-Usámeh in the Musannaf; and as to ↓ سَجَسٌ, it is only a verbal noun (TA, from a note in the handwriting of Aboo-Zekereeyà.)

Hence the saying, (TA,) لَا اتِيكَ سَجِيسَ اللَّيَالِى I will not come to thee to the end of nights: (TA:) or ever; (S, K;) as also سَجِيسَ اللَّيَالِىِ وَ الأَيَّامِ, (TA,) and سجِيسَ الأَوْجَسِ, (S, K,) and سَجِيسَ الأَوْجُسِ, (K,) and سَجِيسَ عُجَيْسٍ: (S, K:) or while time lasts; as also سَجِيسَ الدَّهْرِ, and سَجِيسَ الأَوْجَسِ: (A:) it is from سَجِيسٌ meaning “ turbid, ” because water thus termed is the last that remains: عُجَيْس is a corroborative; and عَجْسُ اللَّيْلِ signifies “ the last part of the night: ” (TA:) or سَجِيسَ اللَّيَالِى means while the nights glide along continuously. (Ham p. 243.)