retard

名词 retard:

1. a person of subnormal intelligence
   同义词：idiot, imbecile, cretin, moron, changeling, half-wit

动词 retard:

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

1. Cold weather retards the growth of the crops.
   寒冷的天气妨碍了庄稼生长。
2. Lack of sun retards plant growth.
   光照不足则植物生长缓慢。

re.tard

v.（动词）
re.tard.ed,re.tard.ing,re.tards
v.tr.（及物动词）
To cause to move or proceed slowly; delay or impede.
减速，拖住：使移动或行进缓慢；延迟或阻碍
v.intr.（不及物动词）
To be delayed.See Synonyms at delay
受到延迟参见 delay
n.（名词）
A slowing down or hindering of progress; a delay.
减速，放慢：前进步伐的减慢或阻碍；延迟
Music A slackening of tempo.
【音乐】 拍子的减慢
[rô.tôrd.] Offensive Slang Used as a disparaging term for a mentally retarded person.
[rô.tôrd.] 【无礼用语】 【俚语】 智力迟钝者：用作精神迟钝者的贬称

来源：
Middle English retarden
中古英语 retarden
from Old French retarder
源自 古法语 retarder
from Latin retard3re
源自 拉丁语 retard3re
re- [re-]
re- [表示.再.]
tard3re [to delay] from tardus [slow]
tard3re [延迟] 源自 tardus [慢的]

【引伸】
retard.er
n.（名词）