dam

Everyday

1. A dam is a strong wall built across a river to hold back the water, making a lake behind it called a reservoir. tree →
2. A dam is also a wall of sticks and mud built by beavers across a stream. tree →
3. To dam a river is to build a dam across it. tree →
4. A dam is also the mother of an animal such as a horse or dog. tree →

In the lessons

In geography and science, dams store water for drinking and farming, stop floods and make electricity with moving water (hydroelectric power). In nature lessons beavers build dams. Phrases: build a dam, the dam burst, a beaver dam, dam up.

Examples

• The dam holds back millions of litres of water. tree →
• Beavers build dams from sticks and mud. tree →
• Water rushing through the dam turns turbines to make electricity. tree →
• After heavy rain, the dam was nearly full. tree →
• We dammed the little stream with stones. tree →
• In the story, the dam burst and the village flooded. tree →
• The lake behind the dam is called a reservoir. tree →
• "Oh, yes, my bonnie lassie," said the mill-dam. tree →

Note

Countable noun: a dam, dams. Verb: dam, dammed, damming (double m). Homophone trap: «damn» (a swear word) sounds the same but has a silent n; do not mix them up.

In Jewish tradition

In the Torah it means the mother of an animal, not a wall that holds back water. In Isaiah it means a barrier that holds back water in the river, as the dams of Egypt.

Interpretation. An animal's young must stay seven days with its mother before it can be offered. A mother bird must be sent away before taking her young, a law the rabbis read as a lesson in kindness. Isaiah's dams are read as part of his warning that Egypt's rivers and trade will fail.

Examples

• Likewise shalt thou do with thine oxen, and with thy sheep; seven days it shall be with its dam; on the eighth day thou shalt give it Me. (Torah EXO.22.30, JPS 1917) tree →
• thou shalt in any wise let the dam go, but the young thou mayest take unto thyself; that it may be well with thee, and that thou mayest prolong thy days. (Torah DEU.22.7, JPS 1917) tree →
• And her foundations shall be crushed, all they that make dams shall be grieved in soul. (Prophets ISA.19.10, JPS 1917) tree →

Note

Countable noun: a dam, dams. Verb: dam, dammed, damming (double m). Homophone trap: «damn» (a swear word) sounds the same but has a silent n; do not mix them up.