Backup is what someone gives when they help or support you. A brand new doctor might need some backup in the emergency room for the first few weeks.

Use the noun backup when you talk about extra assistance or help. Police officers call for backup when they're not sure they can handle a situation on their own, and store cashiers need backup when things get busy and customers start lining up. Another kind of backup is the one you do on your computer — in this case, a backup is the process of copying your data in case you lose the original files.

Definitions of backup
  1. noun
    the act of providing approval and support
    synonyms: backing, championship, patronage
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    type of:
    approval, approving, blessing
    the formal act of approving
  2. noun
    a musical part (vocal or instrumental) that supports or provides background for other musical parts
    synonyms: accompaniment, musical accompaniment, support
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    descant, discant
    a decorative musical accompaniment (often improvised) added above a basic melody
    an improvised musical accompaniment
    type of:
    part, voice
    the melody carried by a particular voice or instrument in polyphonic music
  3. noun
    someone who takes the place of another (as when things get dangerous or difficult)
    synonyms: backup man, fill-in, relief, reliever, stand-in, substitute
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    locum, locum tenens
    someone (physician or clergyman) who substitutes temporarily for another member of the same profession
    double, stunt man, stunt woman
    a stand-in for movie stars to perform dangerous stunts
    alternate, replacement, surrogate
    someone who takes the place of another person
    type of:
    compeer, equal, match, peer
    a person who is of equal standing with another in a group
  4. noun
    an accumulation caused by clogging or a stoppage
    “a traffic backup on the main street”
    “he discovered a backup in the toilet”
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    type of:
    accretion, accumulation
    an increase by natural growth or addition
  5. noun
    (computer science) a copy of a file or directory on a separate storage device
    “he made a backup in case the original was accidentally damaged or erased”
    synonyms: computer backup
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    type of:
    duplicate, duplication
    a copy that corresponds to an original exactly
DISCLAIMER: These example sentences appear in various news sources and books to reflect the usage of the word ‘backup'. Views expressed in the examples do not represent the opinion of or its editors. Send us feedback
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