cataract

A (large) waterfall, specifically one flowing over the edge of a cliff.

A clouding of the lens in the eye leading to a decrease in vision.

(figurative) Something which obscures.

A flood of water; specifically, steep rapids in a river.

(figurative) An overwhelming downpour or rush; a flood.

(historical) A type of governor used in single-acting steam engines, where a flow of water through an opening regulates the stroke.

(no longer used) Synonym of waterspout (“a whirlwind that forms over water”).

(no longer used, rare) Synonym of portcullis (“a gate in the form of a grating which is lowered into place at the gateway of a castle, a fort, etc.”); also, a window grating.

(no longer used) A tool used for breaking flax; a brake.

Of a river, etc.: to fall in the form of a waterfall.

(figurative, rare) To cause (something) to pour or rush like a waterfall.