حيهلحَيْهَلٌ (En-Nadr, AHn, K) and حَيَّهْلٌ and حَيِّهْلٌ (K) A certain shrub of the smaller kind of حَمْض, having no leaves: (En-Nadr, AHn, K:) or the species of حَمْض termed هَرْم: (AA, TA:) a coll. gen. n.: (TA:) n. un. with ة: (K:) so called because, when rain falls upon it, it grows quickly; and when the camels eat it, and do not speedily void their excrement, they die: (AA, TA: [see the next paragraph:]) at the end of a verse of Homeyd Ibn-Thowr, the name is written الحَيَّهُلٌ, with the vowel of the ل transferred to the ه. (AHn, K.) حَيَّهَلَ and حَيَّهَلٌ and حَيَّهَلَنْ and حَيَّهَلًا and حَيَّهَلَا words used in inciting, or urging on: see more in art. حى; (K;) and in art. هل. (TA.)