Sentence:  Her driver was new to the country; he mightn't be prepared for the leaping of the yellow water down dry arroyos, swift as the <WSD>pouncings</WSD> of a cat, or the snake-like slidings of tons of loosened rock and clay from the steep potreros ... 
Meaning of the word marked with <WSD> tags:  A sudden leap, as of an animal when it pounces.