duplicate

1 of 3

adjective

du·​pli·​cate ˈdü-pli-kət 

also ˈdyü-

1

: consisting of or existing in two corresponding or identical parts or examples

duplicate invoices

2

: being the same as another

duplicate copies

duplicate

2 of 3

verb

du·​pli·​cate ˈdü-pli-ˌkāt 

also ˈdyü-

duplicated; duplicating

transitive verb

1

: to make double or twofold

2

a

: to make a copy of

a cell duplicates itself when it divides

b

: to produce something equal to

trying to duplicate last year's success

c

: to do over or again often needlessly

duplicated effort

intransitive verb

: to become duplicated

also : repeat

duplicative

ˈdü-pli-ˌkā-tiv 

also ˈdyü-

adjective

duplicate

3 of 3

noun

du·​pli·​cate ˈdü-pli-kət 

also ˈdyü-

1

a

: either of two things exactly alike and usually produced at the same time or by the same process

b

: an additional copy of something (such as a book or stamp) already in a collection

2

: one that resembles or corresponds to another : counterpart

3

: two identical copies

—used in the phrase in duplicate

Synonyms of duplicate

Adjective

• identical
• similar
• comparable
• same
• analogous

Verb

• copy
• reproduce
• replicate
• render
• imitate

Noun

• image
• replica
• twin
• clone
• picture
• duplication
• portrait
• double

Choose the Right Synonym for duplicate

reproduction, duplicate, copy, facsimile, replica mean a thing made to closely resemble another.

reproduction implies an exact or close imitation of an existing thing.

reproductions from the museum's furniture collection

duplicate implies a double or counterpart exactly corresponding to another thing.

a duplicate of a house key

copy applies especially to one of a number of things reproduced mechanically.

printed 1000 copies of the lithograph

facsimile suggests a close reproduction often of graphic matter that may differ in scale.

a facsimile of a rare book

replica implies the exact reproduction of a particular item in all details

a replica of the Mayflower

but not always in the same scale.

miniature replicas of classic cars

Examples of duplicate in a Sentence

Adjective

I began receiving duplicate copies of the magazine every month.

I had a duplicate key made.

Verb

She duplicated the video to give to family and friends.

Unfortunately, the results of the first study could not be duplicated.

Noun

In case you lose your keys, keep a set of duplicates somewhere safe.

doll carriages that are duplicates of baby carriages

Recent Examples on the Web

Adjective

John Harbaugh still had players wearing their duplicate training camp numbers in an unusually late afternoon practice. — Pat Leonard, New York Daily News, 31 Aug. 2026

Review the Supplement Facts panel carefully to identify duplicate ingredients. — Christopher Bergland, Verywell Health, 27 Aug. 2026

Verb

That Robert Zemeckis film will never be duplicated or topped, but there’s a difference between these films worth teasing out. — Angelica Jade Bastién, Vulture, 28 Aug. 2026

O’Neill said physical branches remain critical for advisory conversations that apps and AI tools cannot duplicate. — Charlotte Observer, 27 Aug. 2026

Noun

Objectors also allege some petition sheets were copies, duplicates or did not apply to the specified referendum. — Addison Wright, Chicago Tribune, 31 Aug. 2026

New features include Automated Bank-Reconciliation that allows JAX to identify unreconciled transactions, duplicates, missing documents and anomalies, then help resolve them while updating the books in real time. — Gene Marks, Forbes.com, 30 Aug. 2026

Word History

Etymology

Adjective

Middle English, from Latin duplicatus, past participle of duplicare to double, from duplic-, duplex

First Known Use

Adjective

15th century, in the meaning defined at sense 1

Verb

15th century, in the meaning defined at transitive sense 1

Noun

1532, in the meaning defined at sense 1a

Phrases Containing duplicate

• duplicate bridge
• in duplicate

Kids Definition

duplicate

1 of 3 adjective

du·​pli·​cate ˈd(y)ü-pli-kət 

1

: having two parts exactly the same or alike

2

: being the same as another

duplicate

2 of 3 verb

du·​pli·​cate ˈd(y)ü-pli-ˌkāt 

duplicated; duplicating

1

: to make double

2

: to make a duplicate of

duplicative

-ˌkāt-iv 

adjective

duplicate

3 of 3 noun

ˈd(y)ü-pli-kət

: a thing that is exactly like another

Medical Definition

duplicate

intransitive verb

du·​pli·​cate ˈd(y)ü-pli-ˌkāt 

duplicated; duplicating

: to become duplicate : replicate

DNA in chromosomes duplicates

Legal Definition

duplicate

1 of 2 transitive verb

du·​pli·​cate ˈdü-pli-ˌkāt, ˈdyü- 

duplicated; duplicating

: to make a duplicate of

duplicative

-ˌkā-tiv 

adjective

duplicate

2 of 2 noun

du·​pli·​cate ˈdü-pli-kət, ˈdyü- 

: either of two things exactly alike and often produced at the same time

specifically : a counterpart identified in the Federal Rules of Evidence Rule 1001 as produced by the same impression as the original or from the same matrix or by means of photography, mechanical, or electronic rerecording, chemical reproduction, or another technique which accurately reproduces the original compare original