WordNet
v. obstruct with, or as if with, a dam; "dam the gorges of the Yangtse River" [syn: dam]
Usage examples of "dam up".
He always tried to be polite even with men he was going to kill, and rudeness here would dam up the man's tongue.
Most of the enemy troops had been forced to charge the dam up the riverbed of the Euphrates.
It had been Peter Gordon who found the ball, not far from the stream the Losers' Club would dam up less than three weeks later.
Drop some of the rubble into the current gorge, build a smaller dam up there, with a relief overflow, and you have the river running into the new gorge and the old one is just a trickle except in winter when it will overflow into the old gorge.
A concrete wall was being constructed between two steep hills to dam up the water flowing from a spring near the top of the mountain.