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

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Examples of backup in a Sentence

Noun 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 New England, which lacks an experienced backup for Brady, has been rumored as a possibility, but would President Donald Trump’s favorite team actually take a shot on a player Trump has so thoroughly scorned? Carl Steward, The Mercury News, "13 questions the 2019 NFL season will answer, from the Browns to Mahomes," 4 Sep. 2019 An apparent computer problem on the Mexican side of the border in Otay Mesa caused a backup of commercial trucks heading into Mexico Thursday morning and prompted the California Highway Patrol to issue a traffic alert that lasted around 90 minutes. Karen Kucher, San Diego Union-Tribune, "Apparent computer glitch causes backup for commercial vehicles heading into Mexico," 29 Aug. 2019 Kane spent the majority of the 2013/14 campaign as backup for Roberto Soldado, and he was made to wait until 7th April 2014 to make his first Premier League start for Spurs., "Harry Kane: Celebrating 8 Years of Tottenham & England's Star Striker," 25 Aug. 2019 Georgia needs to develop a backup for Fromm, identify a big-play receiver and find a consistent pass rush and a lockdown cornerback. Edgar Thompson,, "2019 College Football Countdown: No. 3 Georgia looks to break through, win SEC," 22 Aug. 2019 Rookie Josh Thornhill is winning over defensive coordinator Steve Spagnoula and could end up starting at the safety spot next to Tyrann Mathieu — making Sorensen a $4 million backup for the next couple of years. John Clayton, The Denver Post, "NFL players who could become salary cap casualties before the season," 21 Aug. 2019 After joining the Titans in the second round of the 2016 NFL Draft, Henry served as DeMarco Murray's backup for two seasons. Mark Inabinett |, al, "Nick Saban ‘can’t explain’ Derrick Henry’s unique style," 25 July 2019 Traffic on Marine Drive does not have to stop, often causing long backups during peak travel hours for people wanting to turn from 122nd Avenue., "Portland metro Wednesday traffic: 42nd Avenue Bridge closes for repairs," 17 July 2019 On April 18, 2014, against the Pirates, Maldonado, then a backup for the Brewers, came to bat with a runner on second in the sixth inning. Tim Bannon,, "6 things to know about new Cubs catcher Martin Maldonado, including the time he literally hit the cover off a baseball," 16 July 2019 Recent Examples on the Web: Verb As the end of this chart year looms, the hits of 2019 are regaining traction and climbing back up the tally. Billboard Japan, Billboard, "Sexy Zone Leads Japan Hot 100 as Official HIGE DANdism Continues to Dominate Streaming," 31 Oct. 2019 These standards invariably include some requirement to back up claims, or the right to refuse ads promulgating falsehoods. Raina Kumra, Quartz, "Mark Zuckerberg needs to shut down Facebook’s political ads," 26 Oct. 2019 Because it is being pumped to a higher point, the flow soon reverses, closing the delivery valve, and creating another water hammer that moves back up the inlet pipe, sucking the waste valve downwards into the open position again. Nithyanand Rao, Quartz India, "An IISc scientist joins hands with remote Indian tribals to gently harness a river," 23 Oct. 2019 Dan tore back up the stairs, his heart pounding its way out of his chest. Lizz Schumer, Good Housekeeping, "My Dad's Childhood Home Was Haunted, and He Was the Only One Who Knew," 23 Oct. 2019 Warren hasn't been as consistent as last season (that's almost entirely due to offensive line inexperience and shuffle) and Doaks is just now back up to speed. Fletcher Page,, "What we learned with a lot going on during No. 21 UC football's win against Tulsa," 20 Oct. 2019 But his performance on the field largely seems to back up the claim Shoeless Joe made for the rest of his life. Paul Newberry, The Denver Post, "Newberry: MLB needs to put Shoeless Joe back in the game," 9 Oct. 2019 The Sun used their transition game, leading to layups from Jones and Jasmine Thomas, to tie it back up at 77-77 with 5:35 remaining. Alexa Philippou,, "Connecticut Sun force a Game 5 after thrilling 90-86 win over Washington," 9 Oct. 2019 Many of the assertions in the website are presented merely as questions, and with no or scant information to back up the claim. James Briggs, Indianapolis Star, "Jim Merritt campaign removes false claim about Mayor Joe Hogsett from website," 20 Sep. 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

31 Oct 2019

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


How to pronounce back up (audio)

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

Thesaurus: All synonyms and antonyms for backup

Rhyming Dictionary: Words that rhyme with 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).


not being in agreement or harmony

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