قلس

قَلْسٌ ذ , (A, K, and so in a copy of the S,) or ↓ قَلَسٌ, (A, Mgh, Msb, TA, and so in a copy of the S,) the former being the inf. n., (Mgh, Msb,) and ↓ قَلَسَانٌ, (TA,) [but this last is more like an inf. n.,] What comes forth, (Kh [accord. to the S], or Lth, AZ [accord. to the TA], S, A, Msb, K,) from the throat, (Kh or Lth, S, A, K,) or from the belly, to the mouth, (AZ, Msb,) as much as fills the mouth, or less, (Kh or Lth, S, A, Msb, K,) of [ undigested ] food or drink, (AZ, Msb,) peculiarly, with acidity, and that acid humour itself, (Meyd, as cited by Golius,) whether the person cast it forth or return it to his belly: (AZ, Msb:) when it is repeated, (Kh, S, A, K,) or overcomes, (Lth, TA,) it is termed قَىْءٌ: (Kh or Lth, S, A, K:) or what comes forth, of vomit, being as much as fills the mouth: (Mgh:) pl. أَقْلَاسٌ. (TA.)