blow up

British  

verb

1. to explode or cause to explode

2. (tr) to increase the importance of (something)

   they blew the whole affair up

3. (intr) to come into consideration

   we lived well enough before this thing blew up

4. (intr) to come into existence with sudden force

   a storm had blown up

5. informal to lose one's temper (with a person)

6. informal (tr) to reprimand (someone)

7. informal (tr) to enlarge the size or detail of (a photograph)

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noun

1. an explosion

2. informal an enlarged photograph or part of a photograph

3. informal a fit of temper or argument

4. Also called: blowing up.  informal a reprimand

blow up Idioms  

1. Explode or cause to explode. For example, The squadron was told to blow up the bridge , or Jim was afraid his experiment would blow up the lab . The term is sometimes amplified, as in blow up in one's face . [Late 1500s]

2. Lose one's temper, as in I'm sorry I blew up at you . Mark Twain used this metaphor for an actual explosion in one of his letters (1871): “Redpath tells me to blow up. Here goes!” [ Colloquial ; second half of 1800s]

3. Inflate, fill with air, as in If you don't blow up those tires you're sure to have a flat . [Early 1400s]

4. Enlarge, especially a photograph, as in If we blow up this picture, you'll be able to make out the expressions on their faces . [c. 1930]

5. Exaggerate the importance of something or someone, as in Tom has a tendency to blow up his own role in the affair . This term applies the “inflate” of def. 3 to importance. It was used in this sense in England from the early 1500s to the 1700s, but then became obsolete there although it remains current in America.

6. Collapse, fail, as in Graduate-student marriages often blow up soon after the couple earn their degrees . [ Slang ; mid-1800s]

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Example Sentences

And if so, doesn’t that just blow up Sauer’s theory that the whole point of this clause was to protect the citizenship of these exact people?

From Slate • Apr. 1, 2026

Citing sources in the Danish government, it reported that soldiers, medical supplies and blood were flown into Greenland in January to blow up key airport runways over fears that Trump would invade the arctic island.

From Salon • Mar. 27, 2026

Our hope is that, launching around “Scream 7,” it’s going to catch the zeitgeist and blow up.

From Los Angeles Times • Feb. 25, 2026

The details have to be negotiated, and things could still blow up.

From The Wall Street Journal • Jan. 22, 2026

“I won’t blow up the house,” said Harry, but they weren’t listening.

From "Harry Potter and the Sorcerer's Stone" by J.K. Rowling

Related Words

• blast
• bomb
• burst
• detonate
• dynamite
• erupt
• go off
• rupture
• shatter