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 While the Colts have certainly missed Mack and would be happy to have him Sunday, his backups have fared well in his stead. Jim Ayello, Indianapolis Star, "Colts RB Marlon Mack ‘has a chance’ to play Sunday vs. Tampa Bay," 4 Dec. 2019 Among the unsung influencers during the 49ers’ 10-1 start is Embree, 54, who has played a massive role in developing Kittle and his backup, Ross Dwelley. Eric Branch,, "49ers’ tight end screamer: Embree urges Kittle, Dwelley to push their limits," 28 Nov. 2019 Matthew Stafford was out for a fourth straight game with back and hip injuries and his backup, Jeff Driskel, was limited by a hamstring injury. Larry Lage, Houston Chronicle, "Mitchell's Trubisky’s 3rd TD pass lifts Bears to Thanksgiving win over Lions," 28 Nov. 2019 Grazia capped the night with an interception in the fourth quarter, which prompted LaVerde to bring in his backups on offense. Matt Goul, cleveland, "Kirtland and Luke Gardner outrun Manchester, 32-7, for D-V, Region 17 title," 24 Nov. 2019 But with Austin Hooper out, his backup gets to face a Tampa Bay Buccaneers team allowing 79 yards and a touchdown per game to tight ends, second most in the league. Jim Saranteas, USA TODAY, "Fantasy football deep sleepers: Can Dwayne Haskins hit his stride in Week 12?," 22 Nov. 2019 His backup at tight end, Ross Dwelley, is seldom goofy. Scott Ostler,, "49ers’ super-sub Ross Dwelley putting rocket training to good use," 21 Nov. 2019 There’s certainly a chance Trubisky could miss extended time and a chance that his backup will try to help salvage what’s left of this empty season. Dan Wiederer,, "Column: ‘For whatever reason, here’s Chase Daniel.’ That could become the perfect advertisement for the Bears’ final 6 weeks.," 18 Nov. 2019 Three weeks later his backup, Troy graduate transfer Sawyer Smith, was forced to the sideline as well. Jon Hale, The Courier-Journal, "A never-give-up mentality has Kentucky football on the verge of bowl eligibility yet again," 17 Nov. 2019 Recent Examples on the Web: Verb Ray could go for less, possibly centered around a pitching prospect like Albert Abreu, but interest from other teams could drive the price back up. Jeremy Cluff, azcentral, "Robbie Ray trade speculation between Arizona Diamondbacks, New York Yankees heats up," 6 Dec. 2019 The 21-year-old was then helped back up onto the platform. Fox News, "New York subway platform anti-gay attack sees hammer-wielding man throw victim onto tracks, cops say," 5 Dec. 2019 The addition of the Mitchell twins, who play with the kind of physicality Maryland will need to back up Smith once the Big Ten season starts Saturday against Illinois, has certainly cut into Lindo’s playing time. Don Markus,, "3 takeaways from No. 3 Maryland’s 72-51 win over Notre Dame in the Big Ten/ACC Challenge," 5 Dec. 2019 Homeowners said that the sewage started backing up into their basements around 1 a.m. on Saturday. Michael Wilson, New York Times, "Cooking Grease Down a Drain Eyed in Sewage Flood of at Least 80 Homes," 30 Nov. 2019 With Looney sidelined for all but 10 minutes this season, Golden State has gotten creative at center, leaning on two power forwards — Omari Spellman and Marquese Chriss — to back up Willie Cauley-Stein. Connor Letourneau,, "Warriors’ Kevon Looney on neuropathic condition: ‘I feel confident in my rehab’," 24 Nov. 2019 Steve Castor, an attorney leading the minority party’s investigation, pressed Sondland about his lack of notes and records to back up what his testimony. oregonlive, "Gordon Sondland’s quid pro show," 21 Nov. 2019 Steve Cohen of New York City audio shop In Living Stereo adds that the 1200’s torque got it back up to speed faster than others. Jim Allen, Popular Mechanics, "This Technics Turntable Powered Hip-Hop’s Early Sound," 9 Nov. 2019 But soon enough, like most troubled businesses, SoftBank will have to confront its underlying weakness: a lack of cashflow to back up all of the hype. The Economist, "Hard times for SoftBank," 7 Nov. 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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Time Traveler for backup

Time Traveler

The first known use of backup was in 1801

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Statistics for backup

Last Updated

8 Dec 2019

Cite this Entry

“Backup.” The Dictionary, Merriam-Webster Inc., Accessed 9 December 2019.

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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

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