Retarded
Part of speech: verb
Definition: Past tense of retard; slowed. Past participle of retard; slowed.
Part of speech: adjective
Definition: Delayed in development. Of a person, having mental retardation. By extension, of a person or thing, stupid; senseless; irrational. Under the influence of alcohol.
Cretinous
Part of speech: adjective
Definition: Characteristic of a cretin; very stupid.