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 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 Carlton had 13 points and eight rebounds, with his backup, Isaiah Whaley, getting seven and six in 17 minutes. Dom Amore,, "UConn men come up big down the stretch, score a crowd-pleasing upset win over No. 15 Florida," 17 Nov. 2019 Senior starter Zach Bohannon suffered a minor injury that kept him out for two weeks, and his backup, freshman Dylan Rizk, was injured early in his first start. Adam Lichtenstein,, "Second-round high school playoff picks in Broward and Palm Beach counties," 13 Nov. 2019 With undrafted rookie Brett Rypien as his backup, the Broncos are the only team in the NFL without a quarterback on its roster who has taken an NFL snap. Kyle Newman, The Denver Post, "Broncos place quarterback Joe Flacco on season-ending injured reserve with herniated disc in his neck," 1 Nov. 2019 His backups, Jack Campbell and Cal Petersen, began to be tagged as the club’s goalies of the future. Jack Harris, Los Angeles Times, "Kings’ Jonathan Quick is struggling again this season, but his new coach has faith in him," 14 Oct. 2019 Malcolm Brown is expected to make his second career start in Gurley’s place, with rookie Darrell Henderson as his backup . . ., "Most read on," 13 Oct. 2019 Recent Examples on the Web: Verb Early on a Saturday evening in September, most of the two dozen hospitals in and around Baltimore were posting alerts of varying magnitude: Orange meant ambulances were backed up. John Diedrich,, "Some busy hospitals say they must turn away ambulances. Here's how one state banned the practice," 22 Nov. 2019 The guess here, which was backed up on Wednesday evening by some reporting from Politico, is that the Democrats won’t change course now, and neither will the Republicans. John Cassidy, The New Yorker, "After Gordon Sondland’s Impeachment Testimony: What Will the Republicans Do Now?," 21 Nov. 2019 The solar advocates and customers argue that Alabama Power’s solar fee is not backed up by real-world data and is stifling the rooftop solar industry in Alabama. Dennis Pillion |, al, "Alabama Power solar fee questioned in public hearing," 21 Nov. 2019 State Police said in a tweet at 8:29 a.m. that traffic was backed up about 6 miles., "“For reasons still under investigation, [the car] had left the travel lane and veered off the left side of the off-ramp, continued down an embankment, and struck several trees. The driver . . . was determined to be deceased as a result of injuries sustained in the crash,” the statement said.," 19 Nov. 2019 But the general pattern in the University of Colorado Boulder study is backed up by other research. Joe Lindsey, Outside Online, "Riding an E-Bike Is Not Cheating," 1 Nov. 2019 The Eagles also went three-and-out on the next three possessions after starting with poor field position on each drive as they were backed up toward the goal line. Alex Kushel,, "Visiting Miami Columbus manhandles Atlantic," 1 Nov. 2019 Her experience is backed up by studies, going back to the '80s, that infant girls wear more pink, and own more pink pacifiers and pink jewelry. Marisa Lascala, Good Housekeeping, "Do Girls Really Prefer Pink? There's No Hard-Wired Reason for Girls to Choose Pink Over Blue," 28 Oct. 2019 Cars and trucks hauling horse trailers and campers were backed up for miles on the southbound side of the freeway, some with bedding, large suitcases or pets crammed inside. New York Times, "With Whipping Winds and Power Down, Californians Flee Fires," 27 Oct. 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

24 Nov 2019

Cite this Entry

“Backup.” The Dictionary, Merriam-Webster Inc., Accessed 5 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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