re·tard·ed
adjective/rɪˈtɑːdɪd/
/rɪˈtɑːrdɪd/
(old-fashioned, offensive)- slow to learn or develop mentally; finding it difficult to make progress in learning
This use is considered offensive. You can say that the person has a learning disability or is learning disabled.学习或智力发展缓慢;发现学习上很难取得进步 Oxford Collocations Dictionaryverbs- be
- look
- severely
- mildly
- slightly
- …