غلس2 غلّس, (Msb, K,) inf. n. تَغْلِيسٌ, (S, Mgh, Msb,) He, or it, (a company of men, Msb, K,) journeyed in the غَلَس, or darkness of the last part of the night: (S, K:) or went forth in the غَلَس. (Mgh, Msb.) b2:  غلّسوا, (K,) or غلّسوا المَآءَ, (S,) They came to the water in the غَلَس, or darkness of the last part of the night, (S, K,) or beginning of daybreak: and in like manner you say of birds of the kind called قَطًا, and of [wild] asses. (TA.) b3:  غلّس بِالصَّلَاةِ He performed the prayer [of daybreak] in the غَلَس. (S, * Mgh, Msb.) 4 اغلس He, or it, (a company of men, K,) entered upon the غَلَس, or darkness of the last part of the night. (A, K.) غَلَسٌ The darkness of the last part of the night, (S, A, Msb, K,) when it becomes mixed with the light of the dawn: (TA:) or the beginning of the dawn, until it spreads in the tracts of the horizon: as also غَبَسٌ: both signify blackness mixed with whiteness and redness; like the dawn. (Az, TA.) بِغَلَسٍ In a period of the darkness so called. (S, Msb, K.) [See also غَبَشٌ.]غَلِيسٌ, (Sgh, K,) or غُلَيْسٌ, (JK,) a proper name for An ass; [meaning a wild ass;] (JK, Sgh, K;) because he is أَغْلَس in colour. (JK.) أَغْلَسُ [Of the colour termed غَلَسٌ; i. e., black mixed with whiteness and redness: see غَلِيسٌ]. (JK.) وَقَعَ فِى تُغُلِّسَ, (TA, and so in a copy of the S,) or فِى وَادِى تُغُلِّسَ, (K, TA, and so in another copy of the S,) and تُغَلِّسَ, (TA,) imperfectly  decl., like تُخُيِّبَ (S, K) and تُهُلِّكَ, (K,) He fell into calamity, (Az, S, TA,) or into an abominable calamity, (K, TA,) and that which was vain, unreal, nought, or the like: (Az, S, TA:) originating from the fact that غَارَات [or hostile, or predatory, incursions] (K, TA) generally (TA) took place early, بِغَلَسٍ. (K, TA.)