A vocabulary of landscape — a landscape of words
1190 entries
cataract
A cataract is a large waterfall, or a stretch of river where the whole bed drops steeply through broken water. It is bigger and more continuous than a rapid and in most usage unrunnable. The six cataracts of the Nile set the sense of the word. They are not single falls but long reaches of granite and boulder.
Etymology
The word reached English through Latin from Greek, where it meant something rushing down. But the same Greek word also meant a portcullis, the iron grating dropped to seal a castle gate, and that second sense is what carried the word into medicine. A clouding of the eye’s lens looked to early physicians like something coming down in front of the sight, so the waterfall and the eye condition ended up as the same word.
Notes
The Nile cataracts are numbered from downstream to upstream, which runs backward to the river and forward to anyone sailing up from Egypt. Their positions set the boundary between Egypt and Nubia for thousands of years. The First Cataract at Aswan now lies under the dams.