a barrier to obstruct the flow of water, especially one of earth, masonry, etc., built across a stream or river.
a body of water confined by a dam.
any barrier resembling a dam.
a barrier of concrete, earth, etc, built across a river to create a body of water for a hydroelectric power station, domestic water supply, etc
a reservoir of water created by such a barrier
something that resembles or functions as a dam
1275–1325; Middle English < Middle Dutch, Middle Low German, dam; akin to Old English for-demman to stop up, block
1250–1300; Middle English; variant of dame
A barrier built to block the flow of water is called a dam. If you walk along a stream, you can see where beavers have built a dam out of mud and logs. As a verb, dam means to obstruct or blockade as with a dam. If the kids you're babysitting dam up the bathtub drain when you're not paying attention, the water might overflow and cause a waterfall into the living room downstairs. But water isn't the only thing that can be dammed. You shouldn't dam up your emotions — go ahead and scream if you need to.
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Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
McInnes tried to be measured but the dam burst a little when he spoke about the decisions he feels are going against his club.
From BBC • May 14, 2026
In Kedah's Muda Agricultural Development Authority areas, the main dam reservoir for the region is at just eight percent, according to local reports.
From Barron's • May 8, 2026
“The flood behind the dam has to be released.”
From The Wall Street Journal • May 3, 2026
Twenty-five workers were inside the gold mine when the tailings dam - a structure which holds mining waste - burst on 25 March.
From BBC • Apr. 9, 2026
The capture and confession of Klaus Fuchs were like a dam breaking in Lamphere's and Gardner's years-long accumulation of clues, leads, and evidence of an active Soviet espionage ring in the United States.
From "Spies: The Secret Showdown Between America and Russia" by Marc Favreau
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
