noun, often attributive
back·up | \ˈbak-ˌəp \

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


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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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

But Milwaukee trotted out backup catcher Erik Kratz to the on-deck circle, bluffing with a pinch-hitter that would result in a pitching change. Matthew Defranks,, "A Closer Look: Miami Marlins 5, Milwaukee Brewers 4 (12 innings)," 12 July 2018 We were asked to create a backup option & worked hard to do so. Wendy Dent, WIRED, "The Engineering Behind Elon Musk's Bid to Save Thailand's Cave Boys," 11 July 2018 Distributing air power across the country to smaller, less conspicuous airfields was a smart backup option. Kyle Mizokami, Popular Mechanics, "Watch A-10 Warthogs Landing on the German Autobahn During the Cold War," 5 July 2018 Her backup dancers follow suit in matching pants and dark-pink velvet bodysuits. Mekita Rivas, Teen Vogue, "Janelle Monaé’s Stunning Pride Gown Won the BET Awards Red Carpet," 25 June 2018 Miami moved on from veteran Matt Moore this offseason, leaving Brock Osweiler, Bryce Petty and David Fales as backup options. Jim Reineking, USA TODAY, "Dolphins training camp questions: What will Ryan Tannehill's return mean for Miami?," 25 June 2018 Only four social workers were on hand to care for the hundreds of children, a backup system when Border Patrol agents are not prepared or qualified to deal with the challenges that come with caring for a child. NBC News, "McAllen, Texas, immigration processing center is largest in U.S.," 18 June 2018 That arrangement, where wine dictates the menu as opposed to the other way around, is about as common as letting backup singers perform a solo. Gillian Ferguson, Los Angeles Magazine, "Meet the 26-Year-Old Sommelier Behind Maude’s Coveted Wine Collection," 15 June 2018 With just four musicians, his band filled the Bowl with slithering soul while his backup singers, the Hamiltones, embodied a sort-of Temptations 2000 vibe. Sean J. O'connell,, "At Playboy Jazz Fest, a 17-year-old wonder, an 83-year-old master and tributes to Hef and Miles Davis," 10 June 2018

Recent Examples on the Web: Verb

And even though Rahman used Yelp reviews to back up existing government data, the reviews are still limited. Shoshana Wodinsky, The Verge, "Study claims Airbnb is great for your neighborhood’s economy, if it’s predominantly white," 11 July 2018 In addition to starting at small forward, Anderson is expected to back up point guard Mike Conley, league sources said. Tom Orsborn, San Antonio Express-News, "Anderson appears headed to Memphis," 9 July 2018 There was one major flaw in many of the studies used to back up the claim that a glass of red wine is good for health. Christina Mair,, "Alcohol kills many more Americans than opioids do. Why do we think drinking is healthy?," 9 July 2018 The video, shot by a bystander inside a Starbucks, shows a black woman apparently being ordered out of her car and told to back up to officers, at least four of whom are pointing weapons at her. Scott Berson, sacbee, "Cops bust woman at gunpoint, and video sparks outrage. But she helped kidnap 2 actors, LA police say," 4 July 2018 None other than Ronald Darby, who just happened to back up Winston’s story at Florida State, too. Nancy Armour, USA TODAY, "With Jameis Winston suspension, NFL saying deflating footballs worse than sexual assault," 28 June 2018 The Bulls are thin at small forward, and Hutchison projects to back up starter Justin Holiday. K.c. Johnson,, "Bulls select Boise State's Chandler Hutchison with No. 22 pick in draft," 21 June 2018 At a South Orange six-bedroom that the team flipped in 2017, a toilet started backing up after the house was in contract. New York Times, "For House Flippers, Reality Meets Reality TV," 15 June 2018 The computer had also been used by Ms. Abedin, apparently to routinely back up Clinton’s emails. Warren Richey, The Christian Science Monitor, "Inspector general on Comey: dissecting an error in judgment," 15 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

13 Oct 2018

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

: a situation in which the flow of something (such as traffic) becomes blocked


back·up | \ˈbak-ˌəp \

Kids Definition of backup

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

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Comments on backup

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