cataract是什么意思

cataract

英 ['k?t?r?kt] 美 ['k?t?r?kt]

1. run, rush => race => ract- => cataract "rush down".

cataract 白內(nèi)障，大瀑布

cata-, 向下。-ract, 流，傾瀉，詞源不詳。原指大瀑布，后用做白內(nèi)障的委婉語(yǔ)。

cataract: cataract: [15] Greek kataráktēs meant literally ‘swooping down, rushing down’; it was a derivative of the verb katarássein, a compound formed from the prefix katá- ‘down’ (which appears in a wide range of English words, including cataclysm, catalepsy, catalogue, catapult – literally ‘hurl down’ – and catastrophe) and the verb rássein ‘strike’.

Hence it was applied metaphorically to various things that ‘rush down’, including waterfalls and portcullises. The word passed into English via Latin cataracta, and the sense ‘opacity of the eye’s lens’ developed in the 16th century, probably as a metaphorical extension of the now obsolete ‘portcullis’.
cataract (n.): early 15c., "a waterfall, floodgate," from Latin cataracta "waterfall," from Greek katarhaktes "waterfall, broken water; a kind of portcullis," noun use of an adjective compound meaning "swooping, down-rushing," from kata "down" (see cata-). The second element is traced either to arhattein "to strike hard" (in which case the compound is kat-arrhattein), or to rhattein "to dash, break."

Its alternative sense in Latin of "portcullis" probably was passed through French to form the English meaning "eye disease" (early 15c.), on the notion of "obstruction" (to eyesight).

1. He is an elderly gentleman who had had a cataract operation.: 他是一位曾經(jīng)動(dòng)過(guò)白內(nèi)障手術(shù)的老人.

4. As he stood there, this cataract on a sudden increased in volume.: 他站在那兒, 這道瀑布忽然越來(lái)越大了.

5. The good news from the battlefields is becoming a cataract.: 戰(zhàn)場(chǎng)上傳來(lái)的好消息正在變成一道奔流.