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

Fitbit devices only store data for a week unless backed up to a computer, further complicating the ability to consider long term data when trying to assess if an irregular heart rhythm is a consistent problem over time. Jordyn Hermani, Indianapolis Star, "Fishers teen discovers she has heart defect after wearing Fitbit," 14 July 2018 This is the best group of quarterbacks the Ravens have had since Tyrod Taylor was backing up Flacco. Edward Lee,, "Ravens 2018 position-by-position breakdown: quarterbacks," 9 July 2018 Mack averaged about seven points and four assists last season, backing up D.J. Augustin as the Magic’s point guard. Rick Bonnell, charlotteobserver, "With free-agent guards dwindling, here are 2 remaining options for Charlotte Hornets," 4 July 2018 Dephree,’’ did various dances and the strongman pose as traffic backed up for miles on State Route 110., "Freeway sign climber snarls downtown Los Angeles traffic, does a backflip at end of his protest," 27 June 2018 All lanes were blocked for nearly an hour when a semi tractor-trailer jackknifed shortly after 5 a.m. Traffic is backed up for miles. Jennifer Baker,, "Jackknifed semi snarls SB I-75 at Galbraith Road," 21 June 2018 Kim's bodyguards will certainly travel with him, providing trusted protection to back up local Singapore security that will control the perimeter and crowds, said Choi Kang, vice president of Seoul's Asan Institute for Policy Studies. Foster Klug,, "Isolated Kim Jong Un takes big gamble leaving home for summit with Trump," 9 June 2018 When the lawnmower backed up, she was knocked to the ground and her foot got caught in the blades. Rebecca Bratek, CBS News, "Indiana girl graduates from kindergarten month after losing foot in lawnmower accident," 7 June 2018 Two lanes of the interstate had to be shut down as the police herded the wayward birds, backing up traffic for miles, WCAU reported. Natalie Dreier, ajc, "Peacocks on the loose snarl Philadelphia traffic," 31 May 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

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


something that serves to warn or remind

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