A clouding of the eye lens that makes vision blurry, or a large powerful waterfall.
From Greek 'katarrhaktēs' (falling down), originally describing waterfalls; later applied to eye disease because the clouded lens looks like water rushing down.
One word perfectly describes both a waterfall and an eye disease because ancient doctors thought a cataract was like a 'veil falling down' over the eye.
Complete word intelligence in one call. Free tier — 50 lookups/day.