retarded

nouns

people collectively who are mentally retarded
"he started a school for the retarded"
developmentally challenged, mentally retarded, retarded

adjectives

relatively slow in mental or emotional or physical development
"providing a secure and sometimes happy life for the retarded"
retarded
antonym
precocious
is similar to
retarded in intellectual development
backward, feebleminded, half-witted, slow-witted
is similar to
having a mental age of three to seven years
idiotic, imbecile, imbecilic
is similar to
having a mental age of between eight and twelve years
moronic
is similar to
afflicted with cretinism
cretinous
is similar to
not as far along as normal in development
delayed
is similar to
lacking mental capacity and subtlety
dim-witted, simple, simple-minded
see also
lacking intelligence
"a dull job with lazy and unintelligent co-workers"
stupid, unintelligent