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Synonyms

open up

British  

verb

  1. (intr) to start firing a gun or guns

  2. (intr) to speak freely or without restraint

  3. informal (intr) (of a motor vehicle) to accelerate

  4. (tr) to render accessible

    the motorway opened up the remoter areas

  5. to make or become more exciting or lively

    the game opened up after half-time
"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
open up Idioms  

  1. Spread out, unfold, as in A green valley opened up before us . [Early 1800s]

  2. Begin operation, as in The new store opens up next month . [Late 1700s]

  3. Begin firing, begin attacking, as in The artillery opened up at dawn , or, figuratively, The speaker opened up fiercely on the opposition . [1930s] Also see open fire .

  4. Speak freely and candidly, as in At last the witness opened up and told what happened . “ Colloquial ; c. 1920]

  5. Make an opening by cutting, as in The surgeon opened up the patient's chest .

  6. Become available or accessible, as in With new markets opening up all the time we hope to see our revenues increase dramatically . [Mid-1800s]

  7. Increase the speed of a vehicle, as in Let's see how fast the car will go if you open it up . [ Colloquial ; c. 1920]

  8. Open the door, let me (or us) in, as in Open up! This is the police . [Mid-1900s] Note that in all of these usages except def. 4 and 7, up serves as an intensifier, that is, it emphasizes the verb open .

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Planning Department has estimated that passage of the ordinance, which was first proposed in 2018, would probably open up fewer than 5,500 new potential short-term rentals.

From Los Angeles Times • Apr. 29, 2026

On Wednesday, he said Freddie Mac had actually already accepted a small number of loans scored with VantageScore but that the program would open up to all mortgage lenders effective Wednesday.

From Barron's • Apr. 22, 2026

"Our overriding priority is to de-escalate this conflict, open up the Strait and prevent disruption to passengers."

From BBC • Apr. 21, 2026

A pullback in private lending could also open up more space for bank-led lending and financing.

From The Wall Street Journal • Apr. 20, 2026

I open up the window and cold air rushes into my room just before I get blasted in the face with another snowball.

From "Boy21" by Matthew Quick

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.