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

---

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]

---

Example Sentences

See Examples For:

break down

Those groups create chemically reactive sites, allowing the alkaline treatment to break down materials that would otherwise remain largely inert.

From Science Daily ● Jul. 31, 2026

Ramirez knows from experience that if you use a generator, “it will break down at the worst time.”

From Los Angeles Times ● Jul. 25, 2026

Some have taken to social media to share their tips, vent their frustrations and break down the costs of their outfits.

From BBC ● Jul. 24, 2026

And the hinge can break down over time.

From The Wall Street Journal ● Jul. 22, 2026

Why did the truck have to break down on our last day in Puerto Rico?

From "Marcus Vega Doesn't Speak Spanish" by Pablo Cartaya

Related Words

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