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

After starting the season as backup to Jason Castro, Garver has become an equal part of a tandem, largely because of his bat: .284, 12 HRs, 32 RBIs and team-leading .972 OPS in 41 games. Betsy Helfand, Twin Cities, "Halfway home, Twins in the driver’s seat," 1 July 2019 Looking at Phoenix's roster, Ayton and Saric would likely start with Kaminsky and Baynes serving as backups. Duane Rankin, azcentral, "Phoenix Suns, Frank Kaminsky agree to two-year, $10-million deal, report says," 1 July 2019 Last season Rozier averaged 9 points, 3.9, rebounds, and 2.9 assists per game as Kyrie Irving’s backup. Adam Himmelsbach,, "Could the door open for Al Horford to come back to Celtics?," 30 June 2019 Kerr quickly determined Jones as the definitive starter and Looney as the definitive backup. Mark Medina, The Mercury News, "What’s next for Jordan Bell after he becomes a restricted free agent?," 28 June 2019 In 2017, Modster threw for 671 yards and four touchdowns as Josh Rosen’s backup at UCLA. Brian Howell, The Denver Post, "Pac-12 college football preview 2019: Talented quarterbacks to spark teams," 26 June 2019 Last year’s starter, Kasim Hill, entered his name into the transfer portal, leaving redshirt junior Tyrrell Pigrome as the most likely backup. Matt Murschel,, "2019 College Football Rankings: No. 77 Maryland trusts Mike Locksley to revamp program," 9 June 2019 Instead, its battery acts as an emergency backup in case of a failure of its primary source of electrons, a small diesel generator. John Timmer, Ars Technica, "Workhorse brings an electric pickup truck, helicopter to Manhattan," 19 Aug. 2018 The generators can serve as backup if storms damage the main plants, or if other power systems fail. NBC News, "U.S. plans to remove backup power generators in Puerto Rico. Officials worry it's hurricane season.," 11 July 2018

Recent Examples on the Web: Verb

State workers would sweep the camp of trash every few months, Hammer said, but the tents always popped back up — until early June., "Portland’s homeless campers face new obstacle: piles of boulders," 4 July 2019 Push the corer down into the soil, then pull it back up. Nan Sterman, San Diego Union-Tribune, "34 things to do in the garden in July," 3 July 2019 Hold for a count of three, then jump back up explosively. Rozalynn S. Frazier,, "This 30-Day Bodyweight Challenge Will Tone and Tighten Your Entire Body," 2 July 2019 After forming, the hail falls toward the ground but, if the updrafts are strong enough, the ice is hurled back up into the cloud where more water vapor freezes onto it and the hail stone expands. Washington Post, "The Mexico hailstorm was uncommon and enormous, but not something new," 2 July 2019 This is no longer a show about the ocean as a body of water that can gobble up your secrets, but as a natural force that will inevitably spit them back up at you with a vengeance when the tide rises. Rachel Syme, The New Republic, "Big Little Lies Gets Tough," 28 June 2019 While the school is taking a break for the summer, the programming will start back up again Aug. 15. Jane Stueckemann, Houston Chronicle, "Woodlands’ first Jewish-focused preschool aims to keep traditions alive," 27 June 2019 The number of rides from this group went back up when Bird and Lime left Indianapolis for a few months last summer while the city passed scooter regulations. Ethan May, Indianapolis Star, "How scooters have changed Indianapolis after 1 year," 11 June 2019 Then place fingers lightly on the top part of the cheek, release the muscles to lower them, and lift back up, repeating several times. April Long, Town & Country, "Do Facial Exercises Really Work?," 4 June 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

7 Jul 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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