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

Before games, the Loons’ backup defensive midfielder plays a starring role. Andy Greder, Twin Cities, "A winning vibe: Minnesota United’s success correlates to new DJ’s playlist," 9 Aug. 2019 The Texans started outside linebackers Whitney Mercilus and Brennan Scarlett, Pro Bowl inside linebacker Benardrick McKinney and backup inside linebacker Dylan Cole. Aaron Wilson, Houston Chronicle, "Texans start Joe Webb at QB; Deshaun Watson held out," 8 Aug. 2019 Calhoun worked with the first team at right guard, while Holden moved to backup left tackle after playing right guard. Safid Deen,, "Dolphins training camp Day 6: Stock up, stock down and other observations," 31 July 2019 The stormy Tasmanian weather required backup down jackets. Nina Strochlic, National Geographic, "How this photographer got the photo of her dreams," 22 July 2019 However, Gold claimed that given his relative inexperience, Mauricio Pochettino might feel the need to add further backup up front in the shape of Llorente, regardless of Parrott's unquestionable talent., "Tottenham Offer Fresh Terms to Free Agent Striker After Expiry of Contract," 15 Aug. 2019 Two other deputies who arrived as backup also sprayed the two men who were fighting. Los Angeles Times, "3 deputies cleared in death of Men’s Central Jail inmate who was pepper-sprayed," 14 Aug. 2019 Most of those players will be replaced by returners who served as backups or redshirted a year ago. Jon Hale, The Courier-Journal, "You may see these 5 freshmen on the field a lot for Kentucky football in 2019," 14 Aug. 2019 His absence will give offensive coordinator Chip Long a chance to audition backups Brock Wright and Tommy Tremble. Mike Berardino, Indianapolis Star, "What happens at tight end for Notre Dame following Cole Kmet injury," 13 Aug. 2019

Recent Examples on the Web: Verb

Quarterback Kevin Hogan will get the start, leading rookie Drew Lock in the battle to back up Joe Flacco. Alaa Abdeldaiem,, "Falcons vs. Broncos Live Stream: Watch Hall of Fame Game Online, TV Channel, Time," 1 Aug. 2019 The blast also damaged railroad tracks, forcing 31 trains to back up overnight, authorities said., "1 killed, 5 injured in Kentucky pipeline explosion," 1 Aug. 2019 Trying to back up Walshy a little on the mic and hype up the crowd. Kat Bein, Billboard, "Ape Drums Speaks About Joining Major Lazer: 'I've Got to Think Next Level For Everything'," 31 July 2019 The president frequently cites unemployment figures for African-Americans to back up his claims that his administration is helping the black community, and those figures are at historic lows. Kathryn Watson, CBS News, "Trump says people of Baltimore are "living in hell"," 30 July 2019 Then, when tipsy Tinsley jumped in to back up Barbra’s claims, Luann started to mock her for slurring her words. Kate Hogan,, "All of the Most Epic Real Housewives Brawls, Ever," 26 July 2019 And who is going to back up Franks — redshirt freshman Emory Jones or redshirt junior Kyle Trask? Edgar Thompson,, "Five things to watch during Gators preseason camp," 24 July 2019 Vogt was signed not only to back up Buster Posey and swing a good left-handed bat, but also for his leadership. Henry Schulman,, "'T' time for Giants: Why hitters make that symbol with their fingers when they reach base," 23 July 2019 Kansas City police were on the scene to back up ICE officers, who made the arrest at about 10 a.m. on Monday in front of 4032 Harvard Cir. David K. Li, NBC News, "Caught on tape: ICE officers break window, drag man out of vehicle in front of family," 23 July 2019

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

18 Aug 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).


a period when something is suspended

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