retard

1 of 2

verb

re·​tard ri-ˈtärd How to pronounce retard (audio)
retarded; retarding; retards
Synonyms of retardnext

transitive verb

: to delay or impede the development or progress of : to slow up especially by preventing or hindering advance or accomplishment
chemicals to retard the spread of fire

intransitive verb

: to become delayed : to undergo retardation
retarder noun

retard

2 of 2

noun

re·​tard
plural retards
1
ri-ˈtärd How to pronounce retard (audio) : a holding back or slowing down : retardation
2
ˈrē-ˌtärd How to pronounce retard (audio) offensive : a person affected with intellectual disability
3
ˈrē-ˌtärd How to pronounce retard (audio) informal + offensive : a foolish or stupid person

Synonyms

Verb

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Choose the Right Synonym for retard

delay, retard, slow, slacken, detain mean to cause to be late or behind in movement or progress.

delay implies a holding back, usually by interference, from completion or arrival.

bad weather delayed our arrival

retard suggests reduction of speed without actual stopping.

treatment that retards tumor growth

slow and slacken also imply a reduction of speed, slow often suggesting deliberate intention

she closed her eyes and slowed her breathing

, slacken an easing up or relaxing of power or effort.

on hot days runners slacken their pace

detain implies a holding back beyond a reasonable or appointed time.

unexpected business had detained her

Examples of retard in a Sentence

Verb The chemical will retard the spread of fire. The problems have retarded the progress of the program.
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Verb
As engine revs increase, centrifugal force alters the valve timing by a few degrees, either advancing or retarding it. — Utkarsh Sood june 17, New Atlas, 17 June 2025

Word History

Etymology

Verb

Middle English, from Anglo-French or Latin; Anglo-French retarder, from Latin retardare, from re- + tardus slow

First Known Use

Verb

15th century, in the meaning defined at transitive sense

Noun

1781, in the meaning defined at sense 1

Time Traveler
The first known use of retard was in the 15th century

Rhymes for retard

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Browse Nearby Words

retan
retard
retardance
See all Nearby Words

Cite this Entry

“Retard.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/retard. Accessed 28 Jul. 2025.

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Kids Definition

retard

verb
re·​tard
ri-ˈtärd
: to slow up especially by preventing or checking progress : hinder
retarder noun

Medical Definition

retard

transitive verb
re·​tard ri-ˈtärd How to pronounce retard (audio)
: to slow up especially by preventing or hindering advance or development
retard spoilage
retard hair loss
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