cataract
/ˈkætərækt/noun
1
- a large waterfall大瀑布。
1.1
- a sudden rush of water; a downpour急流, 奔流; 倾盆大雨：
the rain enveloped us in a deafening cataract.
震耳欲聋的暴雨把我们包围了。
2
- a medical condition in which the lens of the eye becomes progressively opaque, resulting in blurred vision白内障：
she had cataracts in both eyes.
她两只眼睛都有白内障。
词源
late Middle English: from Latin cataracta 'waterfall, floodgate', also 'portcullis' (medical sense 2 probably being a figurative use of this), from Greek kataraktēs 'down-rushing', from katarassein, from kata- 'down' + arassein 'strike, smash'.