عشو

عَشًا ذ inf. n. of عَشِىَ: (S, Msb, K:) [used as a simple subst., Weakness of sight: or sightlessness by night with ability to see by day: or] badness of sight by night and by day; as also ↓ عَشَاوَةٌ: (K:) it is in human beings, and beasts of the equine kind (دَوَابّ), and camels, and birds; as is said in the M: (TA:) or it is darkness that happens to the eye: (Er-Rághib, TA:) or blindness; (K, TA;) i. e. absolute destitution of sight. (TA.)