名詞 retarded:

1. people collectively who are mentally retarded
   同義詞：mentally retarded

動詞 retard:

1. slow the growth or development of
   同義詞：check, retard, delay
2. cause to move more slowly or operate at a slower rate
   同義詞：retard
3. be delayed
   同義詞：retard
4. lose velocity; move more slowly
   同義詞：decelerate, slow, slow down, slow up, retard

形容詞 retarded:

1. relatively slow in mental or emotional or physical development

1. A substance that retards or arrests a chemical reaction.
   反催化劑延緩或阻礙化學(xué)反應(yīng)的物質(zhì)
2. Lack of sun retards plant growth.
   光照不足則植物生長緩慢。

re.tard.ed

adj.（形容詞）
Affected with mental retardation.
受智力落后影響的
Relatively slow in mental, emotional, or physical development.
智力遲鈍的，精神發(fā)育遲緩的：在精神、感情或體能發(fā)展上相對緩慢的
n.(used with a pl. verb)（名詞）（與復(fù)數(shù)動詞連用）
Persons affected with mental retardation considered as a group. Often used withthe.
智力遲鈍的：受智力遲鈍影響的人們，被看作一個群體集合。常與the 連用