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.

verb (used with object), dammed, dam·ming.

to furnish with a dam; obstruct or confine with a dam.
to stop up; block up.

Origin of dam

1275–1325; Middle English < Middle Dutch, Middle Low German, dam; akin to Old English for-demman to stop up, block

Synonyms for dam

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for damming

Historical Examples of damming

  • Yes, gentlemen, I stand for locking and damming the Kentucky river!

    Shawn of Skarrow

    James Tandy Ellis

  • Ofttimes he drew his sleeve across his face, but there was no damming that trickle.

    Peter and Wendy

    James Matthew Barrie

  • Beaver commonly fill their ponds by damming a brook or a river.

  • In 48 many cases they are due to the damming up of a stream.

    The Story of the Hills

    H. N. Hutchinson

  • Then, damming up the old channel, he let the stream run into the new.

    Gods and Heroes

    R. E. Francillon

British Dictionary definitions for damming




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

verb dams, damming or dammed

(tr often foll by up) to obstruct or restrict by or as if by a dam

Word Origin for dam

C12: probably from Middle Low German; compare Old Icelandic damma to block up




the female parent of an animal, esp of domestic livestock

Word Origin for dam

C13: variant of dame



interjection, adverb, adjective

(often used in combination) a variant spelling of damn (def. 1), damn (def. 2), damn (def. 3), damn (def. 4) damfool; dammit



symbol for




(Carl Peter) Henrik (ˈhɛnrəɡ). 1895–1976, Danish biochemist who discovered vitamin K (1934): Nobel prize for physiology or medicine 1943
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for damming



late 15c., from dam (n.1). Related: Dammed; damming.



"water barrier," early 14c., probably from Old Norse dammr or Middle Dutch dam, both from Proto-Germanic *dammaz (cf. Old Frisian damm, German Damm), of unknown origin.



"animal mother," c.1300, variant of dame (q.v.), also originally used, like that word, for "lady, mother;" but meanings diverged into separate spellings by 16c.

Online Etymology Dictionary, © 2010 Douglas Harper

damming in Medicine




A barrier against the passage of liquid or loose material, especially a rubber sheet used in dentistry to isolate one or more teeth from the rest of the mouth.


[dăm, däm](Carl Peter) Henrik 1895-1976

Danish biochemist. He shared a 1943 Nobel Prize for the discovery of vitamin K.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Idioms and Phrases with damming


see water over the dam.

The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.