Dam (noun)

1. A barrier constructed across a river or other waterway to hold back water and raise its level, used especially for generating electricity, supplying water, and preventing flooding.
2. A barrier to stop the flow of water or other fluid.
3. A barrier to prevent something from spreading or escaping.
4. Something that stops the normal progress or development of something.
5. A female parent of an animal, especially a domesticated mammal.

Origin:

Late middle english (denoting a barrier or enclosure to keep fish in a pond or river): from old french dame, damme "pond, pool", of unknown origin.

Examples:

1. The Hoover Dam is a concrete arch-gravity dam in the Black Canyon of the Colorado River.
2. The dam was built to control the flow of the river and prevent flooding.
3. The dam burst and the water flooded the town.
4. She put up a mental dam to block out the unpleasant memories.
5. The dam gave birth to six healthy puppies.