boil

¹ American  

[boil] / bɔɪl /

verb (used without object)

1. to change from a liquid to a gaseous state, producing bubbles of gas that rise to the surface of the liquid, agitating it as they rise.

   Water boils at 100°C.

2. to reach or be brought to the boiling point.

   When the water boils, add the meat and cabbage.

3. to be in an agitated or violent state.

   The sea boiled in the storm.

   Synonyms:

   froth, churn, foam

4. to be deeply stirred or upset.

   I didn’t dare open my mouth, as I was boiling with rage.

   Synonyms:

   rage

5. to contain, or be contained in, a liquid that boils.

   The kettle is boiling.

   The vegetables are boiling.

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verb (used with object)

1. to cause to boil or to bring to the boiling point.

   Boil two cups of water.

2. to cook (something) in boiling water.

   Don’t boil the eggs too long if you want soft yolks.

3. to separate (sugar, salt, etc.) from a solution containing it by boiling off the liquid.

   A basic candy can be made by simply boiling sugar in a pan.

noun

1. the act, state, or condition of boiling.

   He brought a kettle of water to a boil.

2. a social event at which food is cooked in boiling water.

   We celebrated harvest and the end of summer with a corn boil in the backyard.

   A jam-packed frosh week kicks off with a crawfish boil and outdoor concert.

3. an area of agitated, swirling, bubbling water, such as part of a rapids.

   My flashlight beam shone on the boil of the river as it beat against the bridge’s foundations.

4. Also called blow.  Civil Engineering. an unwanted flow of water and solid matter into an excavation, due to excessive outside water pressure.

verb phrase

1. boil over

   1. to overflow while boiling or as if while boiling; burst forth; erupt.

      Your soup boiled over and made a mess on the stove.

   2. to be unable to suppress anger, excitement, etc..

      Any mention of the incident makes her boil over.

2. boil out

   1. to clear deposits of calcium, minerals, etc., from (a vehicle’s radiator) by immersing it in boiling water for a time.

   2. to eliminate by or as if by boiling.

      Unlike the germs in your drinking water, lead can't be boiled out.

      The events in the stories have had most of their specialness boiled out by decades of repetition.

   3. boil off.

3. boil down

   1. to reduce the quantity of by boiling off liquid.

      Boil the sauce down till it just covers the cutlets.

   2. to shorten; abridge.

      I think you could boil this lengthy essay down to a couple of pages.

   3. to be simplifiable or summarizable as; lead to the conclusion that; point.

      It all boils down to a basic lack of respect for their employees.

4. boil off Also boil out

   1. to remove or be removed by evaporation, as through boiling.

      The alcohol in this rum cake boils off in baking.

      Maple syrup is made by boiling off the excess water from the sap.

   2. to degum (silk).

   3. to remove (sizing, wax, impurities, or the like) from a fabric by subjecting it to a hot scouring solution.

boil ² American  

[boil] / bɔɪl /

noun

Pathology.

1. a painful, circumscribed inflammation of the skin or a hair follicle, having a dead, suppurating inner core: usually caused by a staphylococcal infection.

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boil ¹ British  

/ bɔɪl /

verb

1. to change or cause to change from a liquid to a vapour so rapidly that bubbles of vapour are formed copiously in the liquid Compare evaporate

2. to reach or cause to reach boiling point

3. to cook or be cooked by the process of boiling

4. (intr) to bubble and be agitated like something boiling; seethe

   the ocean was boiling

5. (intr) to be extremely angry or indignant (esp in the phrase make one's blood boil )

   she was boiling at his dishonesty

6. (intr) to contain a boiling liquid

   the pot is boiling

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noun

1. the state or action of boiling (esp in the phrases on the boil, off the boil )

boil ² British  

/ bɔɪl /

noun

1. Technical name: furuncle.  a red painful swelling with a hard pus-filled core caused by bacterial infection of the skin and subcutaneous tissues, esp at a hair follicle

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boil Scientific  

/ boil /

1. To change from a liquid to a gaseous state by being heated to the boiling point and being provided with sufficient energy. Boiling is an example of a phase transition.

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boil Idioms  

More idioms and phrases containing boil

• make one's blood boil
• watched pot never boils

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Related Words

Boil, seethe, simmer, stew are used figuratively to refer to agitated states of emotion. To boil suggests the state of being very hot with anger or rage: Rage made his blood boil. To seethe is to be deeply stirred, violently agitated, or greatly excited: A mind seething with conflicting ideas. To simmer means to be on the point of bursting out or boiling over: to simmer with curiosity, with anger. To stew is to worry, to be in a restless state of anxiety and excitement: to stew about ( or over ) one's troubles.

Other Word Forms

• boilable adjective

Etymology

Origin of boil¹

First recorded in 1200–50; Middle English boillen, boil(e), buile(n), from Old French boillir, buil(l)ir, from Latin bullīre “to bubble, effervesce, boil,” verb derivative of noun bulla “bubble”

Origin of boil²

First recorded before 1000; Middle English bil(e), bul(e), bel(e), Old English bȳle; cognate with German Beule “boil, hump,” akin to Old Norse beyla “hump, swelling”

Explanation

If you heat water to 212° Fahrenheit, then expect to see it boil — bubbling as it turns from a liquid to a vapor. It's what a watched pot never seems to do! If the water is bubbling and roiling, then it's probably boiling. Cooks boil stuff all the time on the stove; geysers and hot springs boil naturally. And if you spill boiled red cabbage on the new white couch, mom's temper might just boil over. So you see boil can be used both literally and figuratively — to depict boiling hot liquids or boiling hot tempers.

Example Sentences

He added that nearly a fifth of people now only drink bottled water, after SEW issued a boil water notice for several days last year.

From BBC • Apr. 14, 2026

When it comes to soup, there’s a familiar script: You boil, you simmer, you tend.

From Salon • Apr. 3, 2026

Polarized viewpoints often rise to the top: If I read something that either makes my blood boil or completely aligns with my own perspective, I make sure to check the source.

From Slate • Mar. 28, 2026

Upon entering the festival, attendees can fuel up at the Terrace with Irv’s Burgers, a seafood boil from the Boiling Crab or a warm churro from Churrería El Moro.

From Los Angeles Times • Mar. 27, 2026

When we had a few, we’d pluck them and boil them to eat.

From "Lost Boy, Lost Girl" by John Bul Dau

Related Words

• bubble
• evaporate
• poach
• simmer
• steam
• stew