يَأَسٌ

Phthisis, or consumption; synonym سِلٌّ; (M, K;) because he who is affected by it is despaired of; (M;) or [because] the first who was affected by it was اليَأَسُ, (K, TA,) or إِلْيَاس, (TA,) the son of Mudar the son of Nizár: (K, TA:) or, as Suh says, in the R, this disease was called دَاءُ يَاس, or دَاءُ إِلْيَاسَ, because الياس the son of Mudar died of it. (TA.)