A barrier built across a river or stream to hold back the flow of water, often to form a reservoir or generate electricity.
The mighty Hoover dam controls the Colorado River.
Beavers built a small dam across the stream.
✦ From Middle English dam, dame, from Middle Dutch damme and Middle Low German dam, from Proto-Germanic *dammaz (“dam”).
The female parent of a four-legged animal such as a horse or dog.
This mare is a champion dam.
The dam's pedigree is outstanding.
✦ From late Middle English damme, dame (“lady, mother”), variant of dame.
To build a dam across a flowing body of water or to block up with any barrier.
Engineers will dam the valley river next year.
Beavers instinctively dam flowing water.
✦ From the noun sense 1.
