noun, often attributive
back·​up | \ˈbak-ˌəp \

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


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

The Oklahoma mom called 911 for backup and three officers arrived on the scene shortly after. Jennifer Earl, Fox News, "Oklahoma woman mistakes coyote for dog, awakes to wild animal in bedroom: 'He lunged at the door'," 12 Sep. 2018 Keenum was once an undrafted free agent who bounced around from the Texans to the Rams and last season Minnesota, where he was supposed to be a backup and possibly a third-stringer. Andrew Beaton, WSJ, "The NFL’s Quarterback Musical Chairs," 10 Sep. 2018 Kris Dunn might be a career backup and Cameron Payne barely puts out a double-digit scoring average. 8. Peter Dawson, star-telegram, "NBA Mock Draft 5.0: Mavs get two picks in the top 5? Let us explain," 20 June 2018 Finally, Kotb has to call for backup and Guthrie comes in. Ale Russian,, "Cate Blanchett Sits on Sarah Paulson in Wild Today Interview That Goes Off the Rails Fast," 5 June 2018 Lengthy back-ups on Grand at Route 41, especially westbound in the afternoon, often leave lines of traffic stalled for several blocks east of the bridge, and many drivers naturally have learned to avoid the backups and use alternate routes. Jim Newton, Lake County News-Sun, "East Gurnee businesses losing patience and customers over Grand Avenue construction," 30 May 2018 In other parts of the country, malls acquired by Namdar have suffered sewage backups and security problems. Jacob Adelman,, "Owner of former Echelon Mall, called 'slumlord' in Fla., taps overseas cash to become nation's biggest mall buyer," 9 May 2018 But now the Padres will find out about Lopez, who could be a viable backup and left-handed bat off the bench. Kevin Acee,, "Another Padres player down now means another player possibly stepping up for later," 1 May 2018 The officer should wait for backup and EMS assistance before attempting to control the subject. Gina Barton, Milwaukee Journal Sentinel, "Officers who tased a mentally ill man in the shower didn't follow international guidelines," 1 May 2018

Recent Examples on the Web: Verb

Earning back up to 10% of the value of the purchase, shoppers can receive a text message when money hits their account. Sarah Nassauer, WSJ, "Six Tips for Black Friday Shopping: How to Get Discounts, Perks and Bitcoin," 21 Nov. 2018 This creates a hanging bed platform that floats in the center of the camper and pushes back up when not in use. Megan Barber, Curbed, "Chic camper-trailer includes drop-down queen bed," 27 Aug. 2018 Turning the heating temperature down at night and then back up in the morning saves a significant amount of energy, as does turning the air-conditioning temperature up when the home is unoccupied. Henry Gifford, Popular Mechanics, "Your House Is Bleeding You Dry. Here Are 9 Steps To Save You Money.," 8 Aug. 2018 Taking a look at Chen’s numbers a little more closely seems to somewhat back up Straily’s beliefs. Mike Persak,, "Marlins pitchers downplay effect of Marlins Park on better home splits," 14 July 2018 New Everton boss Marco Silva wants to make Zaha a key member of his new attacking line-up but is struggling to convince him to move back up north., "Borussia Dortmund Eye Crystal Palace Star But Face Competition for His Signature From Everton," 10 July 2018 Blood and fluid can also back up into your lungs, leading to fatigue and shortness of breath. Korin Miller, SELF, "13 Surprising Medical Conditions That Can Cause Weight Gain or Loss (and When to Go to the Doctor)," 12 Nov. 2018 Basketball season is back up, baseball season is on its way to the playoffs, and the NFL is in Week 4. Greg Beacham, The Seattle Times, "Lakers loving LeBron’s leadership in 1st practice together," 25 Sep. 2018 Jen backed up her accounts, and investigators believed them. Lauren Smiley, Glamour, "Two White Moms. Six Black Kids. One Unthinkable Tragedy. A Look Inside the ‘Perfect’ Hart Family," 6 Sep. 2018

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

8 Dec 2018

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

: a situation in which the flow of something (such as traffic) becomes blocked


back·​up | \ˈbak-ˌəp \

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

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a soft lustrous wool fabric with mohair

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