retard
1 of 2verb
re·tard ri-ˈtärd 
retarded; retarding; retards
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 2noun
re·tard
plural retards
1
ri-ˈtärd : a holding back or slowing down : retardation
: a holding back or slowing down : retardation 2
ˈrē-ˌtärd offensive : a person affected with intellectual disability
offensive : a person affected with intellectual disability 3
ˈrē-ˌtärd informal + offensive : a foolish or stupid person
informal + offensive : a foolish or stupid person 
Synonyms
Verb
- brake
- decelerate
- slacken
- slow
See all Synonyms & Antonyms 
Example Sentences
Verb The chemical will retard the spread of fire. The problems have retarded the progress of the program.
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
Kids Definition
retard
verb
re·tard ri-ˈtärd
retarded; retarding
: to slow down : delay
Bad weather retarded our progress.
Medical Definition
retard
transitive verb
re·tard ri-ˈtärd
: to slow up especially by preventing or hindering advance or development
retard spoilage
retard hair loss
retards
verb
as in slows
to cause to move or proceed at a less rapid pace an herbicide to retard the growth of weeds Synonyms & Similar Words
Relevance
- slows
- brakes
- inhibits
- hinders
- impedes
- stops
- decelerates
- slackens
- restrains
- halts
- handicaps
- obstructs
- hampers
- curbs
- bottlenecks
- thwarts
- checks
- hobbles
- frustrates
- arrests
- baffles
- holds back
- constrains
- foils
- encumbers
- sets back
- reins
- ties up
- sabotages
- holds up
Antonyms & Near Antonyms
- accelerates
- hastens
- encourages
- rushes
- speeds (up)
- urges
- quickens
- aids
- hurries
- pushes
- spurs
- advances
- drives
- facilitates
- propels
- helps
- stirs
- steps up
- furthers
- forwards
- eases
- goads
- expedites
- dispatches