, (Ṣ, M, Mgh, Mṣb, Ḳ,) aor. يَأْيَسُ (Ṣ, Mṣb, Ḳ) and يَأْيِسُ, (Mṣb,) inf. n. أَيَسٌ, (Mṣb,) or إِيَاسٌ, (Ḳ,) or it has the same inf. n. as يَئِسَ, namely يَأْسٌ, (Ṣ,) with which ↓إِيَاسٌ is syn., (Mgh,) but this last is a contraction of إِيآسٌ, of the measure إِيعَاسٌ, as determined by Az, and is not an inf. n. of أَيِسَ as some think it to be, (Mgh, art. يئِس,) He despaired of it; syn. قنِط: (Ḳ:) a dial. var. of يَئِسَ: (ISk, Ṣ, TA:) or it is not so, but is formed by transposition from يَئِسَ, because it has no [proper] inf. n.; and إِيَاسٌ, the proper name of a man, is not to be adduced in evidence, for it is of the measure فِعَالٌ from الأَوْسُ, “ the act of giving: ” (Preface to the M, quoted in the TA:) if it were a dial. var. of يَئِسَ, they would say إِسْتُ for أَيِسْتُ: (M, TA:) and أُيِسَ, incorrectly written أُويسَ, also signifies the same. (Mgh.)
أَيْسَ: see لَيْسَ.