迟钝的；弱智的；智力发育迟缓的 less developed mentally than is normal for a particular age〖FK(〗用作表语〖FK)〗▲S+be+～Lucy is very retarded and can't read yet.露西在智力方面发育十分迟缓，至今还不识字。〖FK(〗用作宾语补足语〖FK)〗▲S+V+O+～He was so slow that many thought him mentally retarded.他迟钝得很，许多人以为他智力低下 。
Noun:
people collectively who are mentally retarded;
"he started a school for the retarded"
Adjective:
relatively slow in mental or emotional or physical development;
"providing a secure and sometimes happy life for the retarded"
经典引文
Slow, if not downright retarded, in his sexual development.
