/rɪˈtɑːd/
with obj.
- delay or hold back in terms of progress, development, or accomplishment拖延; 使减速; 妨碍, 阻碍：
his progress was retarded by his limp.
由于腿瘸, 他走不快。
/ˈriːtɑːd/
- offensive a mentally handicapped person (often used as a general term of abuse)〈冒犯〉智力迟钝者（常作辱骂用语）。
短语
in retard
- Brit. formal behind or late in terms of development or progress〈英, 正式〉处于落后状态：
I was in retard of them in real knowledge.
我在实际知识方面落后于他们。
派生词
retardation
nounretarder
nounretardment
noun （rare 〈罕〉）词源
late 15th cent.: from French retarder, from Latin retardare, from re- 'back' + tardus 'slow'.