retarded

/ɹɪˈtɑːdɪd/

verb

Meaning

To keep delaying; to continue to hinder; to prevent from progress
"retard the march of an army"
To put off; to postpone.
"to retard a rupture between nations"
To be slow or dilatory to perform (something).
To decelerate; to slow down.
To stay back.

Synonyms

decelerate,

slow,

slow down,

slow up,

decelerate,

hinder,

slow,

slow down,

postpone,

put off,

reluctant,

hang back,

stay back,

hinder,

hold up,

impede

adjective

Meaning

Delayed; delayed in development, hindered; impeded.
Having mental retardation; mentally deficient or underdeveloped.
Specifically, having an IQ below 70.
Extremely stupid.
Designating a parameter of an electromagnetic field which is adjusted to account for the finite speed of radiation.