break down

British  

verb

1. (intr) to cease to function; become ineffective

   communications had broken down

2. to yield or cause to yield, esp to strong emotion or tears

   she broke down in anguish

3. (tr) to crush or destroy

4. (intr) to have a nervous breakdown

5. to analyse or be subjected to analysis

6. to separate or cause to separate into simpler chemical elements; decompose

7. (tr) to saw (a large log) into planks

8. informal

   1. stop it

   2. don't expect me to believe that; come off it

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noun

1. an act or instance of breaking down; collapse

2. short for nervous breakdown

3. an analysis or classification of something into its component parts

   he prepared a breakdown of the report

4. the sudden electrical discharge through an insulator or between two electrodes in a vacuum or gas discharge tube

5. electrical engineering the sudden transition, dependent on the bias magnitude, from a high to a low dynamic resistance in a semiconductor device

6. a lively American country dance

break down Idioms  

1. Demolish, destroy, either physically or figuratively, as in The carpenters broke down the partition between the bedrooms , or The governor's speeches broke down the teachers' opposition to school reform . [Late 1300s]

2. Separate into constituent parts, analyze. For example, I insisted that they break down the bill into the separate charges for parts and labor , or The chemist was trying to break down the compound's molecules . [Mid-1800s]

3. Stop functioning, cease to be effective or operable, as in The old dishwasher finally broke down . [Mid-1800s]

4. Become distressed or upset; also, have a physical or mental collapse, as in The funeral was too much for her and she broke down in tears , or After seeing all his work come to nothing, he broke down and had to be treated by a psychiatrist . [Late 1800s]

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Example Sentences

The chemicals do not break down under normal environmental conditions and research has shown the toxins are in dangerous concentrations in water, soil and food and can also linger in the body.

From BBC • May 28, 2026

There is no consciousness to discover here when you break down what is inside the machine that is A.I.—just formulas.

From Slate • May 25, 2026

Stir in the tomato and cook another 2–3 minutes, until it begins to break down.

From Salon • May 19, 2026

They form as larger plastic materials break down over time and can enter the body through food and drinking water.

From Science Daily • May 18, 2026

Then all of a sudden, out of the blue, Noodles decided to break down how, over the last few days, with all the time to himself, he figured out why he loved comics so much.

From "When I Was the Greatest" by Jason Reynolds

Related Words

• collapse
• crash
• decline
• decrease
• depreciate
• diminish
• dip
• dive
• dwindle
• ease
• go down
• land
• plummet
• plunge
• settle
• sink
• slip
• slump
• stumble
• tumble