noun, often attributive
back·​up | \ ˈbak-ˌəp How to pronounce backup (audio) \

Definition of backup

 (Entry 1 of 2)

1a : one that serves as a substitute or support I brought an extra pencil for backup. a backup plan
b : musical accompaniment The tunes include banjo and guitar backup.
c : additional personnel who provide assistance The police officer called for backup.
2 : an accumulation caused by a stoppage in the flow traffic backup
3 : a copy of computer data (such as a file or the contents of a hard drive) I made a backup copy of the file. also : the act or an instance of making a backup

back up

backed up; backing up; backing up

Definition of back up (Entry 2 of 2)

intransitive verb

: to accumulate in a congested state traffic backed up for miles

transitive verb

1 : to move into a position behind (a teammate) in order to assist on a play
3 : to make a copy of (a computer file or data) to protect against accidental loss or corruption Be sure to back up your work. also : to make copies of all the files on (a device) a program that automatically backs up your hard drive

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Synonyms for backup

Synonyms: Noun

bottleneck, jam, jam-up, logjam, snarl, tailback [British], tie-up

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Examples of backup in a Sentence


His role on the team is to be a backup to the regular quarterback. We have an extra radio as a backup in case this one doesn't work. We have an extra radio for backup. He provides backup for the regular quarterback. She sang backup on his CD.
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Recent Examples on the Web: Noun

The next time you're falsely accused of a crime, don't ask them for backup. Fox News, "Brit Hume on fallout from Kavanaugh hearing; Alan Dershowitz on Rachel Mitchell's performance," 28 Sep. 2018 Daniel then fled on foot while the two officers called for backup from another officer patrolling the neighborhood in a marked police vehicle. Kaylen Ralph, Teen Vogue, "Sacramento Police Released Dashcam Footage of an Officer Hitting a Fleeing Teen With an SUV," 20 Aug. 2018 While police waited for backup, several people inside the home left on their own. Supriya Sridhar, The Courier-Journal, "Man surrenders after hourslong standoff with police in Taylor Berry," 27 June 2018 For backup, Maglite’s compact Mag-Tac CR123 ($83) throws 310 lumens a whopping 600 feet, has a power saving mode, and clips onto your belt. Nick Davidson, Outside Online, "The Ultimate DIY Bug-Out Bag," 27 June 2018 Without waiting for backup, Officer Rosfeld approached the driver’s side of the car and had the driver step out. Matthew Haag, New York Times, "Officer Who Shot Antwon Rose Is Charged With Criminal Homicide," 27 June 2018 Royals first baseman Hunter Dozier struggled to get to it as second baseman Ryan Goins and right fielder Rosell Herrera converged for backup. Maria Torres, kansascity, "After Brandon Maurer blows ninth-inning lead, Royals lose to Astros in 12 innings," 23 June 2018 Goalie Carter Hutton: With the Islanders and Hurricanes still looking for starting goalies and several teams looking for a backup, Hutton should be a hot commodity. Kevin Allen, USA TODAY, "With Ilya Kovalchuk off board, an updated ranking of the top 15 potential free agents," 23 June 2018 Officer Joseph Grams Action: First to confront Brown; called for backup, escalating the situation. Gina Barton, Milwaukee Journal Sentinel, "Here's what happened to the officers involved in the arrest of Milwaukee Bucks player Sterling Brown," 4 June 2018

Recent Examples on the Web: Verb

The Supreme Court punted last term on the constitutionality of political gerrymanders, but lower courts have run the ball back up the field. The Editorial Board, WSJ, "A Gerrymander Mulligan," 25 Mar. 2019 But Sharapova is well on her way, playing for more than a year and getting her ranking back up to No. Tara Sullivan,, "Serena Williams is a superhero," 3 June 2018 Drew Barrymore took a pic showing off her off-duty brows before filming picked back up for Santa Clarita Diet. Glamour, "18 Times Celebrities Challenged Beauty Standards by Sharing Their So-Called 'Flaws'," 6 Apr. 2019 Things picked back up at the BAFTAs once the Cambridges took their seats and the rest of the crowd followed. Erica Gonzales, Harper's BAZAAR, "Kate Middleton and Prince William Joke About the Awkward Silence During Their BAFTAs Entrance," 12 Feb. 2019 The boat approached the capsule stern-first, backing up to get closer. Joe Pappalardo, Popular Mechanics, "How It Works: SpaceX Dragon Capsule Splashdown and Recovery," 8 Mar. 2019 The same preserved tweets from 2012 also show her discussing events at Hillel, backing up her story that she was involved in campus Jewish life. Zack Beauchamp, Vox, "Julia Salazar, the socialist politician accused of lying about her past, explained," 7 Sep. 2018 After the parade, festivities pick back up with a luncheon at LifeSpring Church and an evening talent show. Brandon Rasmussen, idahostatesman, "Elk-calling contests. Fried chicken. And of course, fireworks. Your July 4 guide in SW Idaho," 27 June 2018 Once things pick back up on July 24, one of the key factors in those recruiting battles will happen right here in the state of Florida. Jordan Mcpherson, miamiherald, "Florida recruiting battles this year could be 'fascinating.' Here's where things stand," 25 June 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'backup.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of backup


1910, in the meaning defined at sense 1a


1801, in the meaning defined at intransitive sense

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Statistics for backup

Last Updated

12 May 2019

Look-up Popularity

Time Traveler for backup

The first known use of backup was in 1801

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More Definitions for backup

back up


Financial Definition of back up

What It Is

A back up is an increase in a security’s price, yield, or spread before issuance.

In other circles, back up means replacing a long-maturity security with a short-maturity security in order to capitalize on short-term interest rates that are higher than long-term interest rates.

How It Works

For example, let’s assume that Company XYZ wants to issue $100 million in 10-year bonds. The yields on bonds of similar quality and risk were about 5% when Company XYZ hired the underwriter to handle the bond issue, but since then the required yields have increased to 7%. This means Company XYZ has to issue the bonds at a bigger discount in order to keep the issue competitive, and thus it will obtain less cash from investors at the time of the sale.

This increase in the cost of issuing the securities is a back up.

Why It Matters

Back ups can be very detrimental to issuers, especially if they are relying on a very specific amount of money to come from the issue, and even more especially if the company’s success hinges on the reinvestment of those funds.

Source: Investing Answers



English Language Learners Definition of backup

: a person or thing that can be used to replace or support another person or thing
: help or support provided by additional people or things
US : a situation in which the flow of something (such as traffic) becomes blocked


back·​up | \ ˈbak-ˌəp How to pronounce backup (audio) \

Kids Definition of backup

: a person who takes the place of or supports another The guard called for a backup.

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More from Merriam-Webster on backup

Rhyming Dictionary: Words that rhyme with backup

Thesaurus: All synonyms and antonyms for backup

Spanish Central: Translation of backup

Nglish: Translation of backup for Spanish Speakers

Britannica English: Translation of backup for Arabic Speakers

Comments on backup

What made you want to look up backup? Please tell us where you read or heard it (including the quote, if possible).


something valued as if it were money

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