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

The real issue is whether publishers of scientific journals should retroactively apply contemporary standards regarding duplicate publication or self-plagiarism to historical papers. — Jennifer Ouellette, ArsTechnica, 28 June 2026

For example, a data agent can keep a fundraiser’s data foundation clean and usable, eliminating duplicate records, filling gaps and maintaining data without constant manual upkeep. — Dennis Fois, Forbes.com, 25 June 2026

Verb

Fiber-optic, first-person view (FPV) drones have become a key weapon in the Lebanese militant group Hezbollah’s war against Israel in recent months – bypassing Israel’s sophisticated defense systems by duplicating an asymmetric warfare tactic that first emerged in the Russia-Ukraine war. — Jeremy Diamond, CNN Money, 28 June 2026

Those figures likely included people who have been incommunicado due to the lack of cellphone signals, and some reports may be duplicated. — Arkansas Online, 28 June 2026

Noun

The point is to try to fill up the book, or at least the page, with your favorite team, and then to trade any duplicates or unwanteds with your friends. — Jay Caspian Kang, New Yorker, 30 June 2026

Damaged, worn-out, or expired things get thrown away, items in good condition that thrift stores are looking for can be donated, and holiday items, decor, heirlooms, and duplicates can go into storage. — Nishaa Sharma, The Spruce, 29 June 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