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

That’s when the driver, identified by police as Twyman, starts the engine and begins backing up, catching the deputy with the open door. Los Angeles Times, "34 rounds, 6 gunshot wounds and 3 sheriff’s bullets to the back. Autopsy shows how unarmed man died," 16 Aug. 2019 Drake's backed up the words by dismantling Beatles records. Bryan Alexander, USA TODAY, "Drake's controversial Beatles tattoo puts the rapper on Abbey Road, irking Fab Four fans," 12 Aug. 2019 Wright, who is backing up Thomas Graham Jr. at field cornerback, would be in position to contribute by default given the lack of returning depth in the Oregon secondary., "Oregon expects ‘tremendously impactful’ season from freshman CB Mykael Wright," 10 Aug. 2019 His four, often eye-opening catches for 92 yards in his first preseason game backed up a training camp of similar daily exploits. Dave Hyde,, "Hyde: Preston Williams is a cautionary star of this Miami Dolphins summer | Commentary," 10 Aug. 2019 Cissell backed up and was unhurt, Laird, a 4-year veteran who arrived in the car behind him, was fatally when a round hit above his protective vest. Justin L. Mack, Indianapolis Star, "Remembering Jake Laird, the officer whose death inspired Indiana's 'red flag' law," 7 Aug. 2019 Today, 8chan and The Daily Stormer are both back up. Jim Salter, Ars Technica, "8chan resurfaces, along with The Daily Stormer and another Nazi site," 7 Aug. 2019 Two months later, Neptune’s Storm backed up that win with a victory in the 1 1/8-mile Cinema Stakes. Tod Leonard, San Diego Union-Tribune, "On day of DQs, Big Returns benefits with victory in Graduation Stakes," 2 Aug. 2019 Matthew Rueve backed up last year and is in the signal-caller mix, with Clifford likely to have the ball in his hands in a number of ways. Scott Springer,, "Long Blue Line changes at St. Xavier but expect a solid football team," 2 Aug. 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

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