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

Elite teams managed by him maintain an ideal combination of intelligence within structure, and he has players capable of improvising solutions when patterns break down.

From BBC • Apr. 17, 2026

The following charts break down economists’ forecasts for key indicators and show how the panel’s 2025 consensus compares with actual outcomes.

From The Wall Street Journal • Apr. 15, 2026

As plants break down underwater, they form methane, which then bubbles to the surface.

From Los Angeles Times • Apr. 15, 2026

Katz noted that MCCPs share similarities with PFAS, a group of chemicals often called "forever chemicals" because they break down very slowly in the environment.

From Science Daily • Apr. 11, 2026

She folds laundry, peeking over at me, while I break down some diaper boxes.

From "They Both Die at the End" by Adam Silvera

Related Words

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