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 Fellow rookie Jonah Heim proved a capable backup after replacing Austin Allen on the roster at midseason. Matt Kawahara,, "A’s infield has cornerstones intact for 2021 but questions up the middle," 23 Oct. 2020 Wentz threw a perfect strike to Scott and the backup running back made an excellent catch to give Philadelphia the lead. oregonlive, "Philadelphia Eagles rally to edge the New York Giants: Recap, score, stats and more," 23 Oct. 2020 Philadelphia trailed the Baltimore Ravens 17-0 on Sunday when Eagles backup quarterback Jalen Hurts came on the field for the first time in the second quarter. Mark Inabinett |, al, "Philadelphia Eagles ‘to continue to explore’ Jalen Hurts’ role," 20 Oct. 2020 For the starter tag, the 5-foot-11, 190-pound junior expected to have to unseat Henry Colombi, the backup to first-round NFL draft pick Jordan Love in 2019. Julie Jag, The Salt Lake Tribune, "Utah State QB Jason Shelley, a Utes transfer, already connecting with his new teammates," 20 Oct. 2020 MDCs will be able to use satellite service either as a backup or as the primary Internet connection. Jon Brodkin, Ars Technica, "Microsoft’s new data center in a box will use SpaceX Starlink broadband," 20 Oct. 2020 Google dominates navigation with the Maps and Waze apps, foreign translation (Google Translate), photo backup and sharing (Google Photos), writing/spreadsheets (Google Docs), and online storage (Google Drive). Jefferson Graham, USA TODAY, "Google antitrust: Just how much do you actually use it? Way more than you think," 20 Oct. 2020 The options behind Cousins are veteran backup Sean Mannion, 2019 undrafted Jake Browning and Nate Stanley, a seventh-round rookie out of Iowa. Brian Hall, Star Tribune, "Zimmer, Vikings left to ponder where to turn in 1-5 season," 19 Oct. 2020 Trent Bourguet, Jayden Daniels' backup, texted Yellen to wish him good luck and got a return text after the game. Michelle Gardner, The Arizona Republic, "Seniors Chase Lucas, Jack Jones give ASU veteran duo in back end of defense," 18 Oct. 2020 Recent Examples on the Web: Verb On Wednesday, Daugherty confirmed the population at the Hamilton County Justice Center was back up to 1,205. Madeline Mitchell, The Enquirer, "'It's just hard to contain.' Sheriff's Office says 21 jail employees tested positive for COVID-19," 22 Oct. 2020 Pet Alliance of Greater Orlando initially saw a small reduction of adoptions because of COVID, but is now back up to pre-COVID levels and on track to hit its average yearly target of about 6,000 adoptions. Catherine Matos,, "Finding furever during a pandemic: More Central Floridians adopting dogs, cats," 21 Oct. 2020 Repeat with the remaining apples; if the caramel gets too thick for dipping, gently reheat on the stove top over low heat, back up to around 180 degrees, stirring constantly. Washington Post, "These caramel apples are all treat, no tricks," 21 Oct. 2020 The number dropped in recent days to below 1,000 before jumping back up to 1,349 new infections on Wednesday. Colleen Shalby, Los Angeles Times, "Coronavirus transmission rate grows in L.A. County," 14 Oct. 2020 Pour tomato mixture into broth and bring heat back up to medium. Alex Darus, cleveland, "8 soup recipes to learn before cold weather hits," 14 Oct. 2020 The three appeals court judges granted an interim stay of enforcement of Vance’s subpoena to give the Justice Department time to attempt to appeal the case back up to the Supreme Court. Jerry Dunleavy, Washington Examiner, "Court rejects Trump tax return subpoena appeal," 7 Oct. 2020 Other states have implemented a system where the lowest performing school districts fall temporarily under the control of the state to bring them back up to proficiency. Anchorage Daily News, "Candidate Q&A: Alaska House District 27 — Lance Pruitt," 3 Oct. 2020 The preference is for the county to reach the yellow zone and not move back up to the orange or red zones for two weeks. Billy Kobin, The Courier-Journal, "JCPS board OKs extension of at-home learning, but a return to in-person classes looms," 30 Sep. 2020

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

26 Oct 2020

Cite this Entry

“Backup.” Dictionary, Merriam-Webster, Accessed 26 Oct. 2020.

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More Definitions for backup


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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