English Reference
noun · verb · adjective

duplicate

n. · v. · adj.
US /ˈdupɫəˌkeɪt/ du·pli·cate UK spelling duplicated, duplicates, duplicating

  1. 01 B2 Upper Intermediate

    n.an exact copy of something, like a document or a key.

    n.an identical copy or counterpart of an original object or document.

    Simple

    I keep a duplicate of my house key with a neighbor just in case.

    In context

    The legal team requested a duplicate of the contract to ensure both parties held identical versions of the agreement.

  2. 02 C1 Advanced FormalTechnical Law

    n.a second version of a legal paper that is just as official as the first one.

    n.a document that is the same as another in all essential particulars and carries the same legal validity as the original.

    Simple

    The lawyer signed the duplicate so that both offices had a valid copy.

    In context

    In property law, a duplicate lease is executed so that the landlord and tenant each possess an original instrument of the agreement.

  3. 03 B2 Upper Intermediate

    v.to make an exact copy of something.

    v.to produce an exact copy of a physical or digital object. Transitive use requiring a direct object.

    Simple

    We need to duplicate these files before we start editing them.

    In context

    The software allows users to duplicate entire databases with a single command, ensuring data redundancy across multiple servers.

  4. 04 B2 Upper Intermediate

    v.to do something again in the same way.

    v.to perform an action or process again, often with the goal of achieving the same result.

    Simple

    It will be hard to duplicate the success of last year's festival.

    In context

    Scientists struggled to duplicate the results of the initial experiment, leading to questions about the original methodology.

  5. 05 B2 Upper Intermediate

    adj.exactly the same as another thing.

    adj.being exactly the same as another; existing as a second version of an original.

    Simple

    The museum has duplicate copies of several famous ancient coins.

    In context

    The investigation revealed that the suspect had been using duplicate license plates to avoid detection by traffic cameras.

With no perfect solution yet, companies are adding different sensor systems as well as duplicating those that already come as standard to provide extra back-up.

BBC News· 1 Sept 2026

The Polleux lab has spent more than 15 years studying SRGAP2 , one of several dozen genes that were duplicated specifically in humans.

ScienceDaily· 1 Sept 2026

PIE word *dwóh₁ Borrowed from Latin duplicātus, perfect passive participle of duplicō, see -ate.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Origin Latin duplicātus
Level B2 · Upper Intermediate
Frequency Frequent
Updated