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

However, the 30-year-old struggled to move after missing four set points in a tight tie-break and going a break down at the start of the second.

From BBC • May 26, 2026

Dahlia Lithwick and Mark Joseph Stern break down the Broadview Six dismissal and the Supreme Court’s surprising punt in a major death penalty case.

From Slate • May 23, 2026

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

From Salon • May 19, 2026

Proteins normally break down over time, especially across geological timescales.

From Science Daily • May 14, 2026

In a while it seems as if the lights will never get closer and the dogs break down into a fast trot that carries them all the way in.

From "Woodsong" by Gary Paulsen

Related Words

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